The correct answer is: covalent bonds along polymer chains can stretch and the van der Waals bonds between chains allow chain slippage.
When you stretch a polymer rubber band, the covalent bonds along the polymer chains stretch and rotate, allowing the chains to align in the direction of the stretching force.
Simultaneously, the van der Waals forces between the chains allow them to slip past each other, allowing the band to stretch even further. Van der Waals forces are weak intermolecular forces caused by transient dipoles in the electron distribution of polymer chains.
As a result of the elasticity produced by the covalent bonds between the atoms in the polymer chains, when the stretching force is released, the rubber band returns to its original shape.
For such more question on covalent bonds:
https://brainly.com/question/2746509
#SPJ11
The correct answer is: covalent bonds along polymer chains can stretch and the van der Waals bonds between chains allow chain slippage.
When you stretch a polymer rubber band, the covalent bonds along the polymer chains stretch and rotate, allowing the chains to align in the direction of the stretching force. Simultaneously, the van der Waals forces between the chains allow them to slip past each other, allowing the band to stretch even further. Van der Waals forces are weak intermolecular forces caused by transient dipoles in the electron distribution of polymer chains. As a result of the elasticity produced by the covalent bonds between the atoms in the polymer chains, when the stretching force is released, the rubber band returns to its original shape.
Learn more about polymer here:
brainly.com/question/2746509
#SPJ11
Use the method of initial rates, determine the rate law and rate constant for the reaction given the following data. 2ClO2 + 2OH- --> ClO3- + ClO2- + H2O Experiment [ClO2] [OH-] Initial Rate 1 0.060 0.030 0.0248 2 0.020 0.030 0.00827 3 0.020 0.090 0.0247
The rate law for the reaction is rate = 22.2[ClO₂][OH⁻], and the rate constant is 22.2 M⁻² s⁻¹.
To determine the rate law and rate constant for the given reaction, we can use the method of initial rates, which involves comparing the initial rates of the reaction under different conditions of reactant concentrations.
The general rate law for the reaction can be written as;
rate =[[tex]KClO_{2^{m} }[/tex]][tex][OH^{-]n}[/tex]
where k is the rate constant and m and n are the orders of the reaction with respect to ClO₂ and OH-, respectively.
To determine the orders of the reaction, we can use the data from the three experiments provided and apply the method of initial rates.
Experiment 1;
[ClO₂] = 0.060 M
[OH⁻] = 0.030 M
Initial Rate = 0.0248 M/s
Experiment 2;
[ClO₂] = 0.020 M
[OH⁻] = 0.030 M
Initial Rate = 0.00827 M/s
Experiment 3;
[ClO₂] = 0.020 M
[OH⁻] = 0.090 M
Initial Rate = 0.0247 M/s
We can use experiments 1 and 2 to determine the order of the reaction with respect to [ClO₂] and experiments 1 and 3 to determine the order of the reaction with respect to [OH⁻].
Comparing experiments 1 and 2, we see that the concentration of ClO₂ is reduced by a factor of 3, while the concentration of OH⁻ is held constant. The initial rate is also reduced by a factor of approximately 3. Therefore, the reaction is first order with respect to ClO₂ (m = 1).
Comparing experiments 1 and 3, we see that the concentration of OH⁻ is increased by a factor of 3, while the concentration of ClO₂ is held constant. The initial rate is also increased by a factor of approximately 3. Therefore, the reaction is first order with respect to OH⁻ (n = 1).
Thus, the rate law for the reaction is;
rate = k[ClO₂][OH⁻]
Substituting the values from any of the experiments into the rate law equation, we can solve for the rate constant, k. Let's use experiment 1;
0.0248 M/s = k(0.060 M)(0.030 M)
k = 22.2 M⁻² s⁻¹
To know more about rate law here
https://brainly.com/question/8314253
#SPJ4
Choose starting materials and reagents from the following tables for synthesis of valine by either the acetamidomalonate or reductive amination method. Specify starting material (by number) first. Specify reagents in order of use (by letter) second by nun Examplesents in Starting Materials diethyl acetamidomalonate 4 3-methyl-2-oxo-hexanoic acid diethyl malonate 5 3-methyl-2-oxo-pentanoic acid 3 CH SCH2CH2-CO-CO,H 3-methyl-2-oxo-butanoic acid Reagents a Hyo, heat methyl iodide 9 benzyl bromide b sodium ethoxide 2-bromobutane h Hy over Pac C NH3 /NaBHA 1-bromo-2-methylpropane
The specific starting materials and reagents chosen will depend on various factors such as availability, cost, efficiency, and desired product purity.
To synthesize valine using the acetamidomalonate method, we can use starting material number 4, diethyl acetamidomalonate, and reagents in the following order:
a) Hydrazine, followed by heat, to remove the acetamide group and form the enamine intermediate.
b) Methyl iodide to alkylate the enamine and form the α-alkylated product.
c) Sodium ethoxide to remove the ethyl ester group and form the carboxylic acid intermediate.
d) Hydride reduction over Pd/C catalyst to reduce the carboxylic acid to the alcohol and form valine.
To synthesize valine using the reductive amination method, we can use starting material number 3, 3-methyl-2-oxo-butanoic acid, and reagents in the following order:
a) NH3/NaBH3, to form the imine intermediate.
b) Benzyl bromide to alkylate the imine and form the N-alkylated intermediate.
c) 1-bromo-2-methylpropane to reduce the imine and form the valine product.
It is important to note that these are just two possible routes to synthesize valine, and there are likely many other ways to achieve the same end result. The specific starting materials and reagents chosen will depend on various factors such as availability, cost, efficiency, and desired product purity.
To know more about reagents click here:
https://brainly.com/question/28463799
#SPJ11
what ph value do you anticipate for a mixture of 10. ml of 1.0 m hcl and 5.0 ml of 1.0 m naoh?
The pH value of the mixture of 10 mL of 1.0 M HCl and 5 mL of 1.0 M NaOH is expected to be 1.82.
The pH value of the mixture of 10 mL of 1.0 M HCl and 5 mL of 1.0 M NaOH can be calculated using the formula for pH, which is -log[H+]. In this case, we need to determine the concentration of H+ ions in the solution. The balanced chemical equation for the reaction between HCl and NaOH is:
HCl + NaOH -> NaCl + H2O
The stoichiometry of the reaction is 1:1, which means that the amount of H+ ions generated by the reaction is equal to the amount of OH- ions. Since both the HCl and NaOH solutions are 1.0 M, the total amount of H+ ions and OH- ions in the solution is equal to:
(10 mL HCl x 1.0 mol/L) + (5 mL NaOH x 1.0 mol/L) = 0.01 mol + 0.005 mol = 0.015 mol
Since the amount of H+ ions is equal to the amount of OH- ions, the concentration of H+ ions is 0.015 mol/L. Therefore, the pH value of the solution can be calculated as:
pH = -log[H+] = -log(0.015) = 1.82
Therefore, the pH value of the mixture of 10 mL of 1.0 M HCl and 5 mL of 1.0 M NaOH is expected to be 1.82.
To know more about pH value visit:
https://brainly.com/question/28580519
#SPJ11
Four students were asked to calculate the number of molecules in 25 g of water. which student correctly calculated the number of molecules in the 25 g of water?
In the given scenario, one of the four students correctly calculated the number of molecules in 25 g of water. The explanation for this correct calculation lies in the concept of Avogadro's number and molar mass.
Avogadro's number is a fundamental constant representing the number of entities (atoms, molecules, ions, etc.) in one mole of a substance, which is approximately 6.022 x 10^23. Molar mass refers to the mass of one mole of a substance and is expressed in grams per mole (g/mol).
Out of the four students, the one who correctly calculated the number of molecules in 25 g of water would have followed these steps. Firstly, they would have determined the molar mass of water, which is approximately 18 g/mol (2 hydrogen atoms with a molar mass of 1 g/mol each, and 1 oxygen atom with a molar mass of 16 g/mol). Next, they would have converted the mass of water (25 g) to moles by dividing it by the molar mass (25 g / 18 g/mol ≈ 1.39 mol). Finally, they would have multiplied the number of moles by Avogadro's number to find the number of molecules (1.39 mol x 6.022 x 10^23 molecules/mol ≈ 8.37 x 10^23 molecules). Therefore, this student arrived at the correct answer of approximately 8.37 x 10^23 molecules in 25 g of water.
To learn more about molar mass click here : brainly.com/question/31545539
#SPJ11
What concentration of HF (Ka = 7.2 × 10–4) has the same pH as that of 0.070 M HCl?
Question 10 options:
A)
6.8 M
B)
5.0× 10–6 M
C)
1.0 × 10–2 M
D)
0.070 M
E)
0.15 M
To determine the concentration of HF that has the same pH as 0.070 M HCl, we can use the equation for pH:
pH = -log[H+]
Since HCl is a strong acid, it completely dissociates in water, resulting in the formation of H+ ions. Therefore, the concentration of H+ in a 0.070 M HCl solution is 0.070 M.
Now, we need to find the concentration of HF that produces the same concentration of H+ ions. HF is a weak acid, and it undergoes partial dissociation in water. The dissociation of HF can be represented as follows:
HF (aq) ⇌ H+ (aq) + F- (aq)
The equilibrium constant expression for this dissociation can be written as:
Ka = [H+][F-] / [HF]
Given that Ka = 7.2 × 10^(-4), and we want the same concentration of H+ ions as in the 0.070 M HCl solution, which is 0.070 M, we can set up the equation:
(0.070)(x) / (0.070 - x) = 7.2 × 10^(-4)
Solving this equation will give us the concentration of HF that corresponds to the same pH as the 0.070 M HCl solution.
However, the given options do not include the calculated concentration value. Therefore, we cannot determine the exact concentration of HF based on the provided options.
To know more about concentration refer here
https://brainly.com/question/3045247#
#SPJ11
Hydrogen can be prepared by suitable electrolysis of aqueous magnesium salts. True or false?
The statement "hydrogen can be prepared by suitable electrolysis of aqueous magnesium salts." is true.
Hydrogen can be prepared through electrolysis, which is a process that uses an electric current to drive a non-spontaneous chemical reaction. In this case, an aqueous solution of magnesium salts (such as magnesium sulfate) can be used.
When an electric current is applied to the solution, it causes the ions in the solution to move towards their respective electrodes. The positively charged magnesium ions move towards the cathode, while the negatively charged anions (such as sulfate) move towards the anode.
At the cathode, hydrogen gas is produced as a result of the reduction of water molecules, while the magnesium ions are reduced to solid magnesium.
Meanwhile, at the anode, oxygen gas is produced from the oxidation of water molecules, and the anions in the magnesium salts are oxidized. This process effectively produces hydrogen gas and leaves behind solid magnesium as a byproduct.
To know more about electrolysis click on below link:
https://brainly.com/question/31726896#
#SPJ11
Use the information and table to answer the following question A student is planning to determine the specific heat of iron. To do this experiment the student will need to perform the following procedures: StepProcedure 1 Measure the mass of the iron sample 2 Measure the initial temperature of a known volume of water 3 Heat the iron sample . 4 Place the iron sample in the water What is Step 5 in the experiment?
Based on the given information and procedure steps, Step 5 in the experiment would be to measure the final temperature of the water after adding the heated iron sample.
Why is measuring the final temperature a necessary step?This step is necessary to determine the change in temperature of the water, which is used to calculate the heat gained by the water and the heat lost by the iron sample.
By measuring the initial and final temperatures of the water, the student can determine the temperature change and use it in the calculation of specific heat.
Find out more on experiment here: https://brainly.com/question/25303029
#SPJ1
What is the molality of a solution with 6. 5 moles of salt dissolved in 10. 0 kg of water?
The molality of the solution is 0.65 mol/kg. Molality is defined as the number of moles of solute per kilogram of solvent.
The molality of a solution with 6.5 moles of salt dissolved in 10.0 kg of water can be calculated as follows:
Step 1: Calculate the mass of water in kilograms.
Mass = Density x Volume
Density of water = 1.00 g/cm³
Volume of water = 10.0 L = 10,000 mL = 10,000 cm³
Mass of water = Density x Volume
= 1.00 g/cm³ x 10,000 cm³
= 10,000 g
= 10.0 kg
Step 2: Calculate the molality of the solution.
Molality = moles of solute / mass of solvent (in kg)
We are given moles of solute = 6.5 mol
Mass of solvent = 10.0 kgMolality
= 6.5 mol / 10.0 kg
= 0.65 mol/kg
To learn more about molality, refer:-
https://brainly.com/question/30909953
#SPJ11
between ethanoic acid, methanoic acid, and pentanoic acid, the most soluble of these compounds is . this is due to its .
The most soluble of these compounds is methanoic acid. This is due to its smaller molecular size and ability to form stronger hydrogen bonds with water molecules compared to ethanoic acid and pentanoic acid.
Methanoic acid has only one carbon atom and a carboxylic acid functional group, allowing it to readily interact with water molecules through hydrogen bonding. Ethanoic acid has a longer carbon chain and a weaker hydrogen bonding ability, while pentanoic acid has an even longer carbon chain and is less soluble due to its large molecular size.
In addition, the smaller size of methanoic acid allows it to dissolve more easily in water and form a more stable solution due to its ability to interact more closely with water molecules, leading to higher solubility compared to the other two acids.
To know more about the methanoic acid refer here :
https://brainly.com/question/29587812#
#SPJ11
the phosphates that make up the phosphodiester bonds in dna have pka 2. when the ph of solution is dropped to 2.5, what is the charge of c. elegans dna, which is 97,000-kilo-base-pairs (kbp) long?
At pH 2.5, the phosphates in DNA are fully protonated and positively charged due to the low pH. The pKa of the phosphates is 2, so at pH 2.5, most of the phosphates will be protonated. As a result, DNA at this pH will have a positive charge.
The length of the DNA molecule is given as 97,000 kilobase pairs (kbp), which is a measure of the number of nucleotide pairs in the DNA. To calculate the charge of the DNA.
We need to know the number of phosphates in the molecule, which is equal to twice the number of nucleotide pairs. Therefore, the number of phosphates in the DNA is 194,000.
Since each phosphate group carries a charge of -1 at neutral pH, the total charge on the DNA at pH 2.5 can be calculated by subtracting the number of protons from the total number of phosphates.
At pH 2.5, the number of protons is equal to 10^(2.5-2) times the number of phosphates, or 194,000 * 0.1 = 19,400. Thus, the net charge on the DNA at pH 2.5 is 194,000 - 19,400 = 174,600 elementary charges, or 1.746 x 10⁵ C.
To know more about DNA, refer here:
https://brainly.com/question/21992450#
#SPJ11
Draw all the structures for the conjugate bases formed on deprotonation of the following compounds.
Possible structures include both resonance structures, stereochemical isomers (i.e. EZ isomers for C=C and C-N bonds), and structural isomers. You should be able to come up with at least the number of structures listed parentheticallya. nitropropane (3)
b. 2-pentanone (3)
c. the N-phenylimine of cyclohexanone (2, 3 actually but I only expect you to see '2")
d. diethyl malonate (3)
e. ethyl acetoacetate (5)
a. Nitropropane can form three conjugate bases through deprotonation, including two resonance structures and a structural isomer.
b. Deprotonating 2-pentanone can yield three different conjugate bases with distinct resonance structures.
c. The N-phenylimine of cyclohexanone can form at least two distinct conjugate bases through deprotonation, but possibly up to three depending on how the nitrogen is deprotonated.
d. Deprotonation of diethyl malonate can yield three distinct conjugate bases, including two resonance structures and a structural isomer.
e. Ethyl acetoacetate can form up to five different conjugate bases through deprotonation, including two stereoisomers and three resonance structures.
To calculate the number of conjugate bases, you must identify the acid site and determine how many ways it can be deprotonated. For example, nitropropane has one acid site, the proton on the alpha carbon, which can be deprotonated to form two resonance structures.
Alternatively, the proton on the nitro group can be deprotonated to form a structural isomer. Repeat this process for each compound to arrive at the total number of possible conjugate bases.
For more questions like Conjugate click the link below:
https://brainly.com/question/30086613
#SPJ11
What change in volume results if 170. 0 mL of gas is cooled from 30. 0 °C to 20. 0 °C? (Charles Law)
To calculate the change in volume when 170.0 mL of gas is cooled from 30.0 °C to 20.0 °C using Charles' Law, we need to use the relationship between volume and temperature for an ideal gas. Charles' Law states that at constant pressure, the volume of a gas is directly proportional to its temperature.
By using the formula V₁ / T₁ = V₂ / T₂, where V₁ and T₁ are the initial volume and temperature, and V₂ and T₂ are the final volume and temperature, we can determine the change in volume.
According to Charles' Law, the ratio of the initial volume to the initial temperature is equal to the ratio of the final volume to the final temperature:
V₁ / T₁ = V₂ / T₂
Plugging in the given values:
V₁ = 170.0 mL
T₁ = 30.0 °C + 273.15 = 303.15 K
T₂ = 20.0 °C + 273.15 = 293.15 K
Substituting these values into the equation:
170.0 mL / 303.15 K = V₂ / 293.15 K
To solve for V₂, we rearrange the equation:
V₂ = (170.0 mL / 303.15 K) * 293.15 K
Simplifying the equation:
V₂ ≈ 163.3 mL
Therefore, the change in volume is approximately 163.3 mL when 170.0 mL of gas is cooled from 30.0 °C to 20.0 °C.
To learn more about Charles' Law - brainly.com/question/14842720
#SPJ11
3.00 moles of an ideal gas at 230k and 150 kpa is subjected to isothermal compression and its entropy decreases by 15.0 j/k. what is the pressure of the gas after the compression is finished?
The pressure of the gas after the compression is finished is 147.4 kPa.
To solve this problem, we will need to use the ideal gas law and the second law of thermodynamics. The ideal gas law relates pressure, volume, temperature, and number of moles of an ideal gas. It is given by PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is the temperature.
The second law of thermodynamics states that the entropy of an isolated system always increases or remains constant. In this problem, the entropy of the gas decreases by 15.0 J/K. This means that the gas is not an isolated system, and work must be done on the gas to decrease its entropy.
Since the gas is undergoing isothermal compression, its temperature remains constant at 230 K. Therefore, we can use the ideal gas law to relate the initial and final pressures of the gas:
(P_initial)(V_initial) = (nRT)/(T) = (3.00 mol)(8.31 J/mol·K)(230 K)/(1 atm) = 5596.1 L·atm
The final volume of the gas is not given, but since the temperature remains constant, the gas is compressed isothermally, meaning that the product of pressure and volume remains constant. We can use this fact and the change in entropy to find the final pressure:
(P_final)(V_final) = (P_initial)(V_initial) = 5596.1 L·atm
The change in entropy is given by ΔS = -Q/T, where Q is the heat added to or removed from the system and T is the temperature. In this case, since the temperature is constant, we can write ΔS = -W/T, where W is the work done on the gas. The work done on the gas is given by W = -PΔV, where ΔV is the change in volume. Since the gas is compressed, ΔV is negative, so the work done on the gas is positive:
ΔS = -W/T = (15.0 J/K) = PΔV/T = (P_final - P_initial)(-V_initial)/T
Solving for P_final, we get:
P_final = P_initial - ΔS(T/V_initial) = 150 kPa - (15.0 J/K)(230 K)/(5596.1 L) = 147.4 kPa
For more such questions on compression
https://brainly.com/question/29320737
#SPJ11
how many moles of h2o are required to form 1.6 l of o2 at a temperature of 321 k and a pressure of 0.993 atm ?
The amount of H₂O required to form 1.6 L of O₂ at a temperature of 321 K and a pressure of 0.993 atm is 0.0807 moles.
We can use the ideal gas law to calculate the amount of O₂ in moles:
PV = nRT
n = PV/RT
where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant (0.08206 L atm/mol K), and T is the temperature in Kelvin.
n(O₂) = (0.993 atm)(1.6 L)/(0.08206 L atm/mol K)(321 K) ≈ 0.0657 mol
The balanced chemical equation for the reaction of H₂O and O₂ is:
2H₂O + O₂ → 2H₂O
We can see that for every mole of O₂, we need 2 moles of H₂O. Therefore, the number of moles of H₂O required is:
n(H₂O) = 2n(O₂) = 2(0.0657 mol) ≈ 0.1314 mol
However, this is the amount of H₂O required under standard conditions (0°C and 1 atm). To calculate the amount required under the given conditions, we need to use the combined gas law:
(P₁V₁/T₁)(T₂/P₂) = P₂V₂/T₂
where the subscripts 1 and 2 refer to the initial and final conditions, respectively.
Rearranging and solving for V₁, we get:
V₁ = (P₁V₂T₁)/(P₂T₂) = (1 atm)(1.6 L)(321 K)/(0.993 atm)(273 K) ≈ 5.24 L
So the amount of H₂O required under the given conditions is:
n(H₂O) = 2n(O₂) = 2(0.0657 mol)(1.6 L/5.24 L) ≈ 0.0807 mol
learn more about ideal gas law here:
https://brainly.com/question/30458409
#SPJ11
The solubility of calcium phosphate is 2. 21 x 10- 4 g/L. What are the molar concentrations of the calcium ion and the phosphate ion in the saturated solution? (Molecular wt of calcium phosphate = 310. 18 g/mole)
In a saturated solution of calcium phosphate with a solubility of 2.21 x 10^{-4} g/L, the molar concentration of the calcium ion (Ca^{+2}) is approximately 7.13 x [tex]10^{-7}[/tex] M, and the molar concentration of the phosphate ion (PO_{4}^{-3}) is approximately 3.38 x 10^{-7} M.
To determine the molar concentrations of the calcium ion and the phosphate ion in the saturated solution of calcium phosphate, we need to use the given solubility and the molecular weight of calcium phosphate.
The solubility of calcium phosphate is given as 2.21 x10^{-4} g/L. We can convert this to moles per liter by dividing by the molar mass of calcium phosphate (310.18 g/mol):
2.21 x 10^{-4}g/L / 310.18 g/mol = 7.12 x 10^{-7} mol/L
Since calcium phosphate has a 1:1 ratio of calcium ions ([tex]Ca^{+2}[/tex]) to phosphate ions (PO43-), the molar concentrations of both ions in the saturated solution will be the same. Therefore, the molar concentration of the calcium ion and the phosphate ion is approximately 7.13 x 10^{-7}M.
In conclusion, in a saturated solution of calcium phosphate with a solubility of 2.21 x 1[tex]10^{-4}[/tex] g/L, the molar concentration of the calcium ion (Ca^{+2}) and the phosphate ion ([tex]PO_{4}^{-3}[/tex]) is approximately 7.13 x10^{-7} M.
Learn more about solubility here: https://brainly.com/question/29367909
#SPJ11
the heat of vaporization of mercury is 60.7 kj/mol. for hg(l), s° = 76.1 j mol-1 k-1, and for hg(g), s° = 175 j mol-1 k-1. estimate the normal boiling point of liquid mercury.Teq =
The estimated normal boiling point of liquid mercury is approximately 613.3 K.
The normal boiling point of liquid mercury can be estimated using the Clausius-Clapeyron equation, which relates the heat of vaporization, entropy changes, and the boiling point temperature. The equation is:
ln(P2/P1) = ΔHvap/R * (1/T1 - 1/T2)
Here, ΔHvap is the heat of vaporization (60.7 kJ/mol), R is the gas constant (8.314 J/mol K), and ΔSvap is the difference in entropy between the gaseous and liquid states, which is (175 J mol-1 K-1) - (76.1 J mol-1 K-1) = 98.9 J mol-1 K-1.
Assuming P1 is 1 atm (standard pressure) and P2 is also 1 atm, as we are interested in the normal boiling point, the equation simplifies to:
ln(1) = ΔHvap/ΔSvap * (1/T1 - 1/T2)
Since ln(1) = 0, the equation further simplifies to:
0 = ΔHvap/ΔSvap * (1/T1 - 1/T2)
Assuming T1 is close to the boiling point, we can approximate 1/T1 ≈ 1/T2, and the equation simplifies to:
T2 ≈ ΔHvap/ΔSvap
Now, we can substitute the values and solve for T2:
T2 ≈ (60.7 kJ/mol * 1000 J/kJ) / (98.9 J mol-1 K-1) = 613.3 K
To know more about boiling point visit:
brainly.com/question/2153588
#SPJ11
Number of iron tablets required in 250 cm stock solution. (14.0 mg of Fe2+ per tablet) 2 tablets 10 tablets 20 tablets Before setting up the titration experiment we will need to know how many iron tablets to dissolve in the 250 cm stock solution. Mass (mg) of Fe2+ ions (in 250 cm) Select: Select: Select: Mass (mg) of Fe2+ ions (in 25 cm) Select: Select Select: Select Select Amount (mmol) of Fe2+ ions (in 25 cm) Fill in the missing fields in the table using the drop down menus to determine which option we should use for the titration experiment. Hint: 1 mmol -0.001 mol Molar ratio [Fe2+Mn0,1 5:1 Amount (mmol) of MnO4 ions Select Select: Concentration (mol dm) of KMnOsolution 0.002 0.002 0.002 Volume (cm) of KMnO, solution (mean titre values)
We would need approximately 36 iron tablets and 6.25 cm3 of 0.002 mol dm-3 KMnO4 solution for the titration experiment.
To determine the number of iron tablets required in the 250 cm stock solution, we need to first calculate the mass of Fe2+ ions in the solution.
Assuming that 1 tablet contains 14.0 mg of Fe2+, we can calculate the mass of Fe2+ ions in 250 cm stock solution as follows:
Number of tablets = (mass of Fe2+ ions in 250 cm stock solution) / (mass of Fe2+ ions per tablet)
Number of tablets = (250 cm x 0.001 mol/cm3 x 2 x 55.845 g/mol) / (14.0 mg)
Number of tablets = 500 / 14
Number of tablets = 35.7
Therefore, we would need to dissolve approximately 36 iron tablets in the 250 cm stock solution.
For the titration experiment, we need to determine the amount of Fe2+ ions and MnO4 ions involved. The table is missing some values, but based on the given information, we can fill it in as follows:
Mass (mg) of Fe2+ ions (in 25 cm) = 14.0 mg x (250 cm / 25 cm) = 140.0 mg
Amount (mmol) of Fe2+ ions (in 25 cm) = 0.140 g / 55.845 g/mol = 0.0025 mol
Amount (mmol) of MnO4 ions = 5 x (amount of Fe2+ ions) = 0.0125 mol
Concentration (mol dm) of KMnO4 solution = 0.002 mol dm-3 (given)
Volume (cm3) of KMnO4 solution (mean titre values) = (amount of MnO4 ions) / (concentration of KMnO4 solution) = 6.25 cm3
Therefore, we would need approximately 36 iron tablets and 6.25 cm3 of 0.002 mol dm-3 KMnO4 solution for the titration experiment.
To know more about titration visit :
https://brainly.com/question/29276192
#SPJ11
3TC (C8H11 N3O3S) is a small molecule, antiretroviral medication. What mass (in g) of nitrogen is in 7.43*10^-4 moles of 3TC? The molar mass of C8H11N3O3S is 229.26 g-mol^-1? Data sheet and Periodic Table a. 3.47x10^-3 g b. 3.12x10^-2 g c. 1.70x10^-1 g d. 5.11x10^-1 g
Mass of nitrogen = (2.229*10^-3 mol) x (14.01 g/mol) = 3.12*10^-2 g
The answer is option b) 3.12x10^-2 g.
To calculate the mass of nitrogen in 7.43*10^-4 moles of 3TC, we first need to determine the number of moles of nitrogen present in one mole of 3TC. From the molecular formula of 3TC, we see that there are three nitrogen atoms. Therefore, the number of moles of nitrogen in one mole of 3TC is 3/1 = 3 mol/mol.
Next, we can calculate the number of moles of nitrogen in 7.43*10^-4 moles of 3TC by multiplying this value by the number of moles of 3TC:
moles of nitrogen = (3 mol/mol) x (7.43*10^-4 mol) = 2.229*10^-3 mol
Finally, we can use the molar mass of nitrogen (14.01 g/mol) to calculate the mass of nitrogen in grams:
mass of nitrogen = (2.229*10^-3 mol) x (14.01 g/mol) = 3.12*10^-2 g
Therefore, the answer is option b) 3.12x10^-2 g.
To know more about Molecular Formula visit:
https://brainly.com/question/28647690
#SPJ11
calculate (a) when a system does 41 j of work and its energy decreases by 68 j and (b) for a gas that releases 42 j of heat and has 111 j of work done on it.
a) When a system does 41 J of work and its energy decreases by 68 J, we can use the equation:
ΔE = Q - W
where ΔE is the change in energy, Q is the heat added to the system, and W is the work done by the system.
Given that ΔE = -68 J and W = 41 J, we can rearrange the equation to solve for Q:
Q = ΔE + W
Q = (-68 J) + (41 J)
Q = -27 J
Therefore, the heat removed from the system is -27 J.
b) For a gas that releases 42 J of heat and has 111 J of work done on it, we can use the same equation:
ΔE = Q - W
Given that Q = -42 J (negative because heat is released) and W = 111 J, we can rearrange the equation to solve for ΔE:
ΔE = Q + W
ΔE = (-42 J) + (111 J)
ΔE = 69 J
Therefore, the change in energy of the gas is 69 J.
To know more about energy refer here
https://brainly.com/question/1932868#
#SPJ11
what mass of ni2 is produced in solution by passing a current of 67.0 a for a period of 11.0 h , assuming the cell is 90.0 fficient?
Total, 140 g of Ni²⁺ are produced in solution by passing a current of 67.0 A for a period of 11.0 h, assuming the cell is 90.0% efficient.
To determine the mass of Ni²⁺ produced in solution, we use Faraday's law of electrolysis, which relates the amount of substance produced in an electrolytic cell to the amount of electric charge passed through the cell.
Equation to calculate amount of substance produced wil be;
moles of substance = (electric charge / Faraday's constant) × efficiency
where; electric charge is amount of charge passed through the cell, in coulombs (C)
Faraday's constant is the conversion factor which relates with coulombs to moles of substance, and having a value of 96,485 C/mol e-
efficiency is efficiency of the cell, expressed as a decimal
We can then use the moles of substance produced to calculate the mass using molar mass of Ni²⁺, which is 58.69 g/mol.
First, let's calculate electric charge passed through the cell;
electric charge = current × time
where; current is current passing through the cell, in amperes (A)
time is time the current is applied, in hours (h)
Plugging in the values given;
electric charge = 67.0 A × 11.0 h × 3600 s/h
= 267,732 C
Next, let's calculate moles of Ni²⁺ produced;
moles of Ni²⁺ = (267,732 C / 96,485 C/mol e-) × 0.90
= 2.39 mol
Finally, let's calculate mass of Ni²⁺ produced:
mass of Ni²⁺ = moles of Ni²⁺ × molar mass of Ni²⁺
mass of Ni²⁺ = 2.39 mol × 58.69 g/mol = 140 g
Therefore, 140 g of Ni²⁺ are produced in solution.
To know more about Faraday's law of electrolysis here
https://brainly.com/question/13104984
#SPJ4
What is the correct name for FeO?a. iron oxideb. iron(II) oxidec. iron(III) oxided. iron monoxidee. iron(I) oxide
The correct name for FeO is iron(II) oxide. Iron(II) oxide indicates that the iron ion in the compound has a +2 oxidation state.
The formula FeO consists of one iron atom with a +2 charge and one oxygen atom with a -2 charge. Therefore, the Roman numeral (II) is used to denote the oxidation state of iron.
Iron(II) oxide is commonly known as ferrous oxide. It is a black, powdery substance that occurs naturally as the mineral wüstite. It is used in various applications, including as a pigment in ceramics and as a catalyst in chemical reactions. Iron(II) oxide can also be produced by the reduction of iron(III) oxide with carbon monoxide at high temperatures.
It's worth noting that iron(III) oxide (Fe2O3) is another common iron oxide, commonly known as ferric oxide or rust. Iron monoxide (FeO) is not an accurate name for the compound since it implies a single atom of oxygen, which is not the case. Similarly, iron(I) oxide does not represent the correct oxidation state for iron in FeO.
Learn more about FeO here:
https://brainly.com/question/14040243
#SPJ11
calculate the solubility of fe oh 2 in water at 25°c
To calculate the solubility of Fe(OH)2 in water at 25°C, we need to know its solubility product constant (Ksp). The solubility product constant is a measure of the equilibrium between the dissolved and solid states of a sparingly soluble substance.
For Fe(OH)2, the Ksp value at 25°C is approximately 4.87 × 10^-17. We can use this value to find the solubility of Fe(OH)2. First, let's write the balanced chemical equation and the corresponding solubility product expression:
Fe(OH)2 (s) ⇌ Fe²⁺ (aq) + 2 OH⁻ (aq)
Ksp = [Fe²⁺] [OH⁻]²
Let x represent the solubility of Fe(OH)2 in moles per liter. Then, [Fe²⁺] = x and [OH⁻] = 2x. Substitute these values into the solubility product expression:
4.87 × 10⁻¹⁷ = x (2x)²
Solve for x:
4.87 × 10⁻¹⁷ = 4x³
x³ = 1.2175 × 10⁻¹⁷
x = (1.2175 × 10⁻¹⁷)^(1/3)
x ≈ 2.30 × 10⁻⁶6 M
The solubility of Fe(OH)₂ in water at 25°C is approximately 2.30 × 10⁻⁶ moles per liter.
Learn more about chemical here:
https://brainly.com/question/29240183
#SPJ11
Complete and balance these equations to show how each element reacts with hydrochloric acid. Include phase symbols. reaction a: Mg(8)+HCl(aq) reaction b: Zn(s)+HCl(aq)
The balanced reaction A is: Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) and The balanced reaction B is: Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
For reaction a:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
This reaction involves magnesium (Mg) reacting with hydrochloric acid (HCl) to produce magnesium chloride (MgCl2) and hydrogen gas (H2).
For reaction b:
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
This reaction involves zinc (Zn) reacting with hydrochloric acid (HCl) to produce zinc chloride (ZnCl2) and hydrogen gas (H2).
Here is a detailed and step-by-step explanation for completing and balancing the reactions of Mg and Zn with hydrochloric acid, including phase symbols.
Reaction A: Mg(s) + HCl(aq)
1. Write the unbalanced equation with products: Mg(s) + HCl(aq) → MgCl2(aq) + H2(g)
2. Balance the equation: Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
The balanced reaction A is: Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
Reaction B: Zn(s) + HCl(aq)
1. Write the unbalanced equation with products: Zn(s) + HCl(aq) → ZnCl2(aq) + H2(g)
2. Balance the equation: Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
The balanced reaction B is: Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
Learn more about hydrochloric acid
https://brainly.com/question/15231576
#SPJ11
pump nitrate down to the u6 to so that metal reducing bacteria can reduce the uranium to u4 which is insoluble and unable to move though the groundwater
The process you're describing is known as in situ bioremediation. Essentially, it involves using naturally occurring microorganisms to break down contaminants in the environment. In this case, the goal is to reduce uranium contamination in groundwater.
To do this, the first step is to pump nitrate down to the U6 zone. This creates an environment where metal-reducing bacteria can thrive. These bacteria then work to convert the uranium to U4, which is insoluble and cannot move through the groundwater. This effectively removes the uranium from the water, reducing contamination levels.
It's worth noting that this process is not a quick fix and may take some time to be effective. Additionally, it requires careful monitoring to ensure that it is working properly and not causing any unintended environmental impacts. However, when done correctly, in situ bioremediation can be a powerful tool for reducing contamination and improving environmental health.
To know more about groundwater click here:
https://brainly.com/question/10005777
#SPJ11
a solution with a ph of 9.100 is prepared using aqueous ammonia and solid ammonium chloride. what is the ratio of [nh3] to [nh4 ] in the solution? the kb of ammonia is 1.76 × 10−5.
The ratio of [NH3] to [NH4+] in the solution is approximately 2.54:1.
To solve this problem, we need to use the equilibrium constant expression for the reaction between ammonia (NH3) and ammonium ion (NH4+):
NH3 + H2O ⇌ NH4+ + OH-
The equilibrium constant expression is:
Kb = [NH4+][OH-]/[NH3]
We can use the pH and the Kb value to calculate the concentrations of NH3, NH4+, and OH- in the solution.
First, we need to calculate the concentration of OH-:
pH = 14 - pOH
pOH = 14 - 9.100 = 4.900
[OH-] = 10^(-pOH) = 7.94 × 10^(-5) M
Next, we can use the Kb expression to calculate the concentration of NH4+:
Kb = [NH4+][OH-]/[NH3]
[NH4+] = Kb * [NH3]/[OH-]
[NH4+] = (1.76 × 10^(-5)) * [NH3]/(7.94 × 10^(-5))
[NH4+] = 0.394 * [NH3]
Finally, we can use the fact that the total concentration of ammonia (NH3 + NH4+) is equal to the concentration of NH3 + NH4+:
[NH3] + [NH4+] = [NH3] + 0.394 * [NH3]
[NH4+] = 0.394 * [NH3]
Therefore, the ratio of [NH3] to [NH4+] is:
[NH3]/[NH4+] = 1/0.394 = 2.54
Click the below link, to learn more about Equilibrium constant:
https://brainly.com/question/31321186
#SPJ11
A 10 g sample of a compound that consists of carbon and hydrogen is found to consist of 7. 99 g of carbon and 2. 01 g of hydrogen.
What is the empirical formula and molecular formula of this compound?
(Molar mass is 30. 07 g/mol)
To determine the empirical formula and molecular formula of the compound, we first need to find the molar ratios of carbon and hydrogen.
Step 1: Calculate the moles of carbon and hydrogen.
Moles of carbon = mass of carbon / molar mass of carbon
Moles of carbon = 7.99 g / 12.01 g/mol
Moles of carbon = 0.665 mol
Moles of hydrogen = mass of hydrogen / molar mass of hydrogen
Moles of hydrogen = 2.01 g / 1.008 g/mol
Moles of hydrogen = 1.996 mol
Step 2: Divide the moles by the smallest mole value.
Dividing both moles by 0.665 (smallest mole value), we get approximately:
Carbon: 0.665 mol / 0.665 = 1 mol
Hydrogen: 1.996 mol / 0.665 = 3 mol
Step 3: Determine the empirical formula.
Based on the molar ratios, the empirical formula is CH3.
Step 4: Calculate the empirical formula mass.
Empirical formula mass = (molar mass of carbon × number of carbon atoms) + (molar mass of hydrogen × number of hydrogen atoms)
Empirical formula mass = (12.01 g/mol × 1) + (1.008 g/mol × 3)
Empirical formula mass = 12.01 g/mol + 3.024 g/mol
Empirical formula mass = 15.034 g/mol
Step 5: Calculate the ratio of the molar mass of the compound to the empirical formula mass.
Ratio = molar mass of the compound / empirical formula mass
Ratio = 30.07 g/mol / 15.034 g/mol
Ratio = 2
Step 6: Multiply the subscripts in the empirical formula by the ratio calculated in Step 5 to obtain the molecular formula.
Molecular formula = (C1H3) × 2
Molecular formula = C2H6
Therefore, the empirical formula of the compound is CH3, and the molecular formula is C2H6.
Learn more about empirical formula here
https://brainly.com/question/32125056
#SPJ11
when this equation is balanced with the smallest set of whole numbers, what is the coefficient for n2? ___n2h4(g) ___n2o4(g)___n2(g) ___h2o(g)
The balanced equation for the reaction:
n2h4(g) + n2o4(g) → n2(g) + h2o(g)
is:
2N2H4(g) + N2O4(g) → 3N2(g) + 4H2O(g)
The coefficient for n2 in the balanced equation is 3.
The given chemical equation is:
n2h4(g) + n2o4(g) → n2(g) + 2h2o(g)
To balance this equation with the smallest set of whole numbers, we need to adjust the coefficients in front of the chemical formulas until we have the same number of each type of atom on both sides of the equation.
First, we can balance the nitrogen atoms by placing a coefficient of 1 in front of N2 on the right-hand side:
n2h4(g) + n2o4(g) → 2n2(g) + 2h2o(g)
Next, we balance the hydrogen and oxygen atoms by placing a coefficient of 4 in front of H2O on the right-hand side:
n2h4(g) + n2o4(g) → 2n2(g) + 4h2o(g)
Now we have the same number of each type of atom on both sides of the equation. Therefore, the coefficient for N2 is 2.
Therefore, the balanced chemical equation is:
N2H4(g) + N2O4(g) → 2N2(g) + 4H2O(g)
Click the below link, to learn more about Balancing equation:
https://brainly.com/question/12405075
#SPJ11
Rank each of the bonds identified in order of increasing wavenumber: Hint : Stronger bonds (triple bonds > double bonds single bonds) vibrate at higher frequencies:
The order of increasing wavenumber for the bonds is: single bonds < double bonds < triple bonds. This reflects the relative strengths of the bonds, with triple bonds being the strongest and single bonds being the weakest.
The wavenumber of a bond in a molecule is directly proportional to the frequency of its vibration. Stronger bonds vibrate at higher frequencies, and weaker bonds vibrate at lower frequencies.
Using this information, we can rank the bonds identified in order of increasing wavenumber as follows:
1. Single bonds: These bonds are the weakest and vibrate at the lowest frequency, so they have the lowest wavenumber.
2. Double bonds: These bonds are stronger than single bonds and vibrate at a higher frequency, so they have a higher wavenumber.
3. Triple bonds: These bonds are the strongest and vibrate at the highest frequency, so they have the highest wavenumber.
Therefore, the order of increasing wavenumber for the bonds is single bonds < double bonds < triple bonds. This order reflects the relative strengths of the bonds, with triple bonds being the strongest and single bonds being the weakest.
To know more about wavenumber refer here:
https://brainly.com/question/31452434#
#SPJ11
calculate the volume of h2 that will be produced from the complete consumption of 10.2 g zn in excess 0.100 m hcl (p = 725 torr, t = 22.0 °c).
The volume of H₂ produced from the complete consumption of 10.2 g Zn in excess 0.100 M HCl at a pressure of 725 torr and a temperature of 22.0 °C is 4.81 L.
The balanced chemical equation for the reaction between zinc (Zn) and hydrochloric acid (HCl) is:
Zn + 2HCl → ZnCl₂ + H₂
From the equation, we can see that 1 mole of Zn reacts with 2 moles of HCl to produce 1 mole of H₂.
First, let's calculate the number of moles of Zn in 10.2 g:
molar mass of Zn = 65.38 g/mol
moles of Zn = 10.2 g / 65.38 g/mol = 0.156 moles
Since the HCl is in excess, it won't be fully consumed, and we can assume that all of the Zn will react to produce H2.
Next, we can use the ideal gas law to calculate the volume of H2 produced:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.
First, let's convert the pressure from torr to atm:
1 torr = 1/760 atm
P = 725 torr * (1/760) = 0.954 atm
Next, let's convert the temperature from Celsius to Kelvin:
T = 22.0 °C + 273.15 = 295.15 K
Now we can substitute the values into the ideal gas law and solve for V:
V = nRT / P
V = 0.156 mol * 0.0821 L·atm/mol·K * 295.15 K / 0.954 atm
V = 4.81 L
Learn more about volume: https://brainly.com/question/1578538
#SPJ11
choose the l-aldohexose that gives the same alditol when treated with sodium borohydride.
The L-aldohexose that gives the same alditol as glucose when treated with NaBH4 is galactose.
What happens when an L-aldohexose is treated with sodium borohydride (NaBH4)?When an L-aldohexose is treated with sodium borohydride (NaBH4), it is reduced to form an alditol.
To determine which L-aldohexose will give the same alditol as another, we need to compare the structures of the alditols produced.
For example, if we treat glucose and mannose with NaBH4, we will obtain the corresponding alditols, glucoitol and mannoitol, respectively. However, these two alditols have different structures, so they will not be the same.
On the other hand, if we treat glucose and galactose with NaBH4, we will obtain the corresponding alditol, glucitol (also known as sorbitol), which is the same for both sugars. This is because glucose and galactose are epimers at the C4 position, which means that they differ only in the configuration of the hydroxyl group at this position. This difference does not affect the way the sugar is reduced by NaBH4, so both glucose and galactose will give the same alditol, glucitol.
Therefore, the L-aldohexose that gives the same alditol as glucose when treated with NaBH4 is galactose.
Learn more about L-aldohexose
brainly.com/question/14300876
#SPJ11