Answer:
Reduce the intensity of radiations
Explanation:
Atomic Emission Spectroscopy is the study of electromagnetic radiations that are emitted by matter when it is excited. It is used to analyze intensity of light emitted. To end the radiations of AFS and AES their intensity is reduced and they are gradually rejected. It is not possible to completely eliminate the radiations immediately.
Calculate the amount of heat (kcal) released when 50.0g of steam at 100 degrees celsius hits the skin, condenses and cools to a body temperature of 37 degrees celsius
Answer:
[tex]Q=-126.1kJ[/tex]
Explanation:
Hello,
In this case, by means of the released heat, we need to consider the cooling of water in two steps:
1. Condensation of steam at 100 °C.
2. Cooling of water from 100 °C to 37 °C.
Therefore, we need the enthalpy of condensation of water that is 40.65 2258.33 J/g and the specific heat that is 4.18 J/g°C for the same amount of cooled water to obtain:
[tex]Q=50.0g*[-2258.33\frac{J}{g}+4.18\frac{J}{g\°C}(37-100)\°C]\\\\Q=-126.1kJ[/tex]
Best regards.
If one contraction cycle in muscle requires 55 kJ55 kJ , and the energy from the combustion of glucose is converted with an efficiency of 35%35% to contraction, how many contraction cycles could theoretically be fueled by the complete combustion of one mole of glucose? Round your answer to the nearest whole number.
Answer:
18 moles
Explanation:
Here the combustion of one mole of glucose ----> carbon dioxide + water, releases 2870 kilojoules / moles.
_______________________________________________________
With one contraction cycle requiring 55 kilojoules,
2870 / 55 ≈ 52.18
And with the efficiency being 35 percent,
52.1818..... * 0.35 = ( About ) 18 moles
Hope that helps!
The bromine test (part d) is often used as an indication of unsaturation(double and triple bonds). Explain why your result for trichloroethylene and toluene were different than for the simple alkene produc
Answer:
Toluene is an aromatic compound not an alkene
Bromine test is used to determine the presence of unsaturation in the given compound. The trichloroethylene does not have any unsaturation while toluene have double bonds of benzene ring. Therefore, the Bromine test can differentiate between trichloroethylene and toluene.
What is degree of unsaturation?The degree of unsaturation of an organic compounds can be categorised two types: saturated and unsaturated. Saturated compounds are those that have only single bonds. An unsaturated compound are those that has a double bond, triple bond, and/or ring(s).
The alkanes with only single bonds are classified as saturated whereas the alkenes and alkynes with double and triple bonds are classified as unsaturated hydrocarbons.
The degree of unsaturation formula helps in finding whether a compound is saturated or unsaturated.
In the Bromine test when the bromine solution will be added into the compound if the brown color of the solution will disappear it means the unsaturation is present in the given compound.
Therefore, the we can distinguish between trichloroethylene and toluene with bromine test.
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Draw structural formulas for all the alkene(s) formed by treatment of each haloalkane or halocycloalkane with sodium ethoxide in ethanol. Assume that elimination occurs by an E2 mechanism.
Answer:
Explanation:
Kindly note that I have attached the complete question as an attachment.
Here, we are told that elimination occurs by an E2 mechanism. What this means is that the hydrogen and the halogen must be above and below for the reaction to proceed.
The possible products are as follows;
Please check attachment for complete equations and diagrams of compounds too.
Look at the picture and observations below.
Observations: The bee's wings are moving very fast.
The bee's wings are much smaller than its body.
what’s the answer ?
Answer:
How are bees able to fly?
Explanation:
describe how would you use chromatography to show whether blue ink contains a single purple dye or a mixture of dyes
Explanation:
if the solution placed on the chromatography is pure there will be formation of one spot from the baseline and will go farthest to the front line unlike the impure one
With ink chromatography, a small amount of ink is added to the paper, one end is submerged in water, and the different colors of the ink are revealed as the water moves up the paper. All of this is made possible by the water base and variety of salabilities or densities that make up ink.
What is chromatography ?Separating mixture's constituent parts by chromatography is a method. The mixture is dissolved in a material known as the mobile phase to start the process, which then transports it through a material known as the stationary phase.
A little dot of the ink to be separated is placed at one end of a strip of filter paper to perform ink chromatography. The paper strip's opposite end is submerged in a solvent. The solvent moves up the paper strip, dissolving the chemical combination as it goes and pulling it up the paper.
Throughout the experiment, the dyes are pulled along by the mobile phase (water) as it gently advances up the stationary phase (paper).
Thus, With ink chromatography, a small amount of ink is added to the paper, one end is submerged in water.
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The acetic acid/acetate buffer system is a common buffer used in the laboratory. Write the equilibrium equation for the acetic acid/acetate buffer system. The formula of acetic acid is CH3CO2H .
Answer:
CH₃CO₂H + H₂O ⇄ CH₃CO₂⁻ + H₃O⁺
Explanation:
A buffer is defined as the mixture of a weak acid and its conjugate base or vice versa.
For the acetic acid buffer, CH₃CO₂H is the weak acid and its conjugate base is the ion without H⁺, that is CH₃CO₂⁻. The equilibrium equation in water knowing this is:
CH₃CO₂H + H₂O ⇄ CH₃CO₂⁻ + H₃O⁺In the equilibrium, the acid is dissociated in the conjugate base and the hydronium ion.
The acetic acid/acetate buffer system is a common buffer used in the laboratory, the equilibrium equation for the acetic acid/acetate buffer system. The formula of acetic acid is CH3CO2H -
CH₃CO₂H + H₂O ⇄ CH₃CO₂⁻ + H₃O⁺
An acid buffer is a solution that contains roughly the same concentrations of a weak acid and its conjugate base.
an acetate buffer contains roughly equal concentrations of acetic acid and acetate ion.Both are in chemical equilibrium with each other.The equation is:
CH₃CO₂H + H₂O ⇄ CH₃CO₂⁻ + H₃O⁺
where CH₃CO₂H - acetic acid
and, CH₃CO₂⁻ acetate ion
Thus, CH₃CO₂H + H₂O ⇄ CH₃CO₂⁻ + H₃O⁺ is the equilibrium equation for the acetic acid/acetate buffer system.
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The cytochromes are heme‑containing proteins that function as electron carriers in the mitochondria. Calculate the difference in the reduction potential (ΔE∘′) and the change in the standard free energy (ΔG∘′) when the electron flow is from the carrier with the lower reduction potential to the higher. cytochrome c1 (Fe3+)+e−↽−−⇀cytochrome c1 (Fe2+)E∘′=0.22 V cytochrome c (Fe3+)+e−↽−−⇀cytochrome c (Fe2+)E∘′=0.254 V Calculate ΔE∘′ and ΔG∘′ .
Complete Question
The complete question is shown on the first uploaded image
Answer:
The change in reduction potential is [tex]\Delta E^o=E^o_{cell} = 0.034 V[/tex]
The change in standard free energy is [tex]\Delta G^o = -3.2805 \ KJ/mol[/tex]
Explanation:
From the question we are told that
At the anode
[tex]cytochrome \ c_1 \ (Fe^{3+}) + e^-[/tex]⇔[tex]cytochrome \ c_1 \ (Fe^{2+}) \ \ E^o = 0.22 \ V[/tex]
At the cathode
[tex]cytochrome \ c \ (Fe^{3+}) + e^-[/tex]⇔[tex]cytochrome \ c \ (Fe^{2+}) \ \ E^o = 0.254 \ V[/tex]
The difference in the reduction potential is mathematically represented as
[tex]\Delta E^o = E^o_{cathode} - E^o_{anode}[/tex]
substituting values
[tex]\Delta E^o = 0.254 - 0.220[/tex]
[tex]\Delta E^o=E^o_{cell} = 0.034 V[/tex]
The change in the standard free energy is mathematically represented as
[tex]\Delta G^o = -n * F * E^o_{cell}[/tex]
Where F is the Faraday constant with value F = 96485 C
and n i the number of the number of electron = 1
So
[tex]\Delta G^o = -(1) * 96485 * 0.034[/tex]
[tex]\Delta G^o = -3.2805 \ KJ/mol[/tex]
The reaction of 15 moles carbon with 30 moles O2 will
result in a theoretical yield of moles CO2.
Answer:
The amount of Co2 generated is 15 moles
Explanation:
It bears the same ratio with Carbon meaning oxygen was used in excess
a solid x when heated gives up a brown gas. If x is soluble in excess sodium hydroxide solution but insoluble in excess ammonium hydroxide solition. What is X?
Answer:
Lead (ii) nitrate
Explanation:
It is soluble in sodium hydroxide but insoluble in aqueous ammonia
When heated it produces nitrogen (IV) oxide that isbrown in colour
A protein's secondary structure arises due to interactions between amino acids. Two common secondary structures found in many proteins are alpha helices and beta sheets. Classify the following statements as pertaining to alpha helices or beta sheets.
1. Keep their shape due to hydrogen bonds between adjacent polypeptides chains
2. form long thin structures important for transmembrane proteins
3. flat zig zag like structure
4. a rigid spring like structure around a central axis
Answer:
Alpha helixes:
- form long thin structures important for transmembrane proteins
- have a rigid spring like structure around a central axis
Beta sheets:
- Keep their shape due to hydrogen bonds between adjacent polypeptides chains
- have a flat zig zag like structure
Explanation:
Alpha helices and beta pleated sheets are two types of secondary structure found in proteins.
Alpha helix: In this structure, the polypeptide backbone is tightly wound around an imaginary central axis drawn longitudinally through the center with the R groups of the amino acids protruding outward from the helical backbone. This structure looks like a spring and could either be a left-handed or right-handed helix, though the left-handed helix has not been observed in proteins. Each turn of the helix includes about 3.6 amino acid residues.
The alpha helix is stabilized by a hydrogen bond between the hydrogen atom attached to the electronegative nitrogen atom of a peptide linkage and the electronegative carbonyl oxygen atom of the fourth amino acid on the amino-terminal side of that peptide bond.
Alpha-helices due to their structure, are the most common transmembrane proteins- protein structure element that crosses biological membranes.
Beta sheets: In the beta conformation, the backbone of the polypeptide chain is extended into a zigzag structure. The zigzag polypeptide chain can be arranged side by side to form a structure resembling a series of pleats known as beta sheets. Hydrogen bonds formed between adjacent segments of the polypeptide chain functions to stabilize the structure.
The beta comformation in the form of turns is common in globular proteins.
How does the number of valence electrons in an atom relate to the element's
placement on the periodic table?
A. Elements in the same group have the same number of valence
electrons.
B. The number of valence electrons increases as the atomic number
increases.
O C. The number of valence electrons is the same for all elements on
the periodic table.
D. Elements in the same period have the same number of valence
electrons.
Harvey kept a balloon with a volume of 348 milliliters at 25.0˚C inside a freezer for a night. When he took it out, its new volume was 322 milliliters, but its pressure was the same. If the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer?
Answer:
[tex]T2=276K[/tex]
Explanation:
Given:
Initial volume of the balloon V1 = 348 mL
Initial temperature of the balloon T1 = 255C
Final volume of the balloon V2 = 322 mL
Final temperature of the balloon T2 =
To calculate T1 in kelvin
T1= 25+273=298K
Based on Charles law, which states that the volume of a given mass of a ideal gas is directly proportional to the temperature provided that the pressure is constant. It can be applied using the below formula
[tex](V1/T1)=(V2/T2)[/tex]
T2=( V2*T1)/V1
T2=(322*298)/348
[tex]T2=276K[/tex]
Hence, the temperature of the freezer is 276 K
Answer: 276 kelvins
Explanation:
Why need to add NaAlF6 to Al2O3?
When comparing the two chair conformations for a monosubstituted cyclohexane ring, which type of substituent shows the greatest preference for occupying an equatorial position rather than an axial position
Answer:
See the explanation
Explanation:
In this case, we have to keep in mind that in the monosubstituted product we only have to replace 1 hydrogen with another group. In this case, we are going to use the methyl group [tex]CH_3[/tex].
In the axial position, we have a more steric hindrance because we have two hydrogens near to the [tex]CH_3[/tex] group. If we have more steric hindrance the molecule would be more unstable. In the equatorial positions, we don't any interactions because the [tex]CH_3[/tex] group is pointing out. If we don't have any steric hindrance the molecule will be more stable, that's why the molecule will the equatorial position.
See figure 1
I hope it helps!
On a hot summer day, the density of air at atmospheric pressure at 35.5°C is 1.1970 kg/m3. (a) What is the number of moles contained in 1.00 m3 of an ideal gas at this temperature and
Complete question:
On a hot summer day, the density of air at atmospheric pressure at 35.5°C is 1.1970 kg/m3. (a) What is the number of moles contained in 1.00 m3 of an ideal gas at this temperature and pressure.
Answer:
The number of moles contained by an ideal gas at this temperature and pressure is 41.32 moles.
Explanation:
Given;
density of dry air, ρ = 1.1970 kg/m³
temperature of the air, T = 35.5°C = 273 + 35.5 = 308.5 K
air volume, V = 1 m³
Apply ideal gas law for dry to calculate the air pressure;
[tex]P = \rho R_dT[/tex]
where;
P is the air pressure
ρ is the air density
Rd is gas constant for dry air = 287 J/kg/K
P = 1.197 x 287 x 308.5 = 105,981.78 Pa
(a) Now, determine the number of moles contained by an ideal gas at this temperature and pressure, by applying ideal gas law;
PV = nRT
where;
P is the pressure of the gas (Pa)
V is the volume of the gas (m³)
n is number of gas moles
R is gas constant = 8.314 m³.Pa / mol.K
T is temperature (K)
n = (PV) / (RT)
n = (105,981.78 x 1) / (8.314 x 308.5)
n = 41.32 moles
Therefore, the number of moles contained by an ideal gas at this temperature and pressure is 41.32 moles.
The number of moles of an ideal gas at this temperature and pressure is 41.5 moles.
Given that;
Density of dry air = 1.1970 kg/m3
Pressure of dry air = ?
Temperature of dry air = 35.5°C + 273 = 308.5 K
Hence;
P = Density × gas constant of dry air × Temperature
P = 1.1970 kg/m3 × 287.1 J/Kg/K × 308.5 K
P = 106019 Pa or 1.05 atm
Using the ideal gas equation;
PV = nRT
n = PV/RT
n = 1.05 atm × 1000 L/0.082 atmL/K.mol × 308.5 K
n = 41.5 moles
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Duncan knows that it takes 36400 cal of energy to heat a pint of water from room temperature to boiling. However, Duncan has prepared ramen noodles so many times he does not need to measure the water carefully. If he happens to heat 0.800 pint of room-temperature water, how many kilojoules of heat energy will have been absorbed by the water at the moment it begins to boil?
Answer:
[tex]\large \boxed{\text{122 000 J}}[/tex]
Explanation:
1. Calculate the energy needed
[tex]\text{Energy} = \text{0.800 pt} \times \dfrac{\text{36 400 cal}}{\text{1 pt}} = \text{ 29 120 cal}[/tex]
2. Convert calories to joules
[tex]\text{Energy} = \text{29 120 cal} \times \dfrac{\text{4.184 J}}{\text{1 cal}} = \textbf{122 000 J}\\\\\text{The water will have absorbed $\large \boxed{\textbf{122 000 J}}$}[/tex]
How many moles of each product form when the given amount of each reactant completely reacts. C3H8(g)+5O2yields 3CO2(g)+4H2O(g). 4.6 moles of C3H8
Answer: 13.8 moles of [tex]CO_2[/tex] and 18.4 moles of [tex]H_2O[/tex] will be produced
Explanation:
The given balanced reaction is;
[tex]C_3H_8(g)+5O_2(g)\rightarrow 3CO_2(g)+4H_2O(g)[/tex]
Given : 4.6 moles of [tex]C_3H_8[/tex]
According to stoichiometry :
1 mole of [tex]C_3H_8[/tex] give = 3 moles of [tex]CO_2[/tex]
Thus 4.6 moles of [tex]C_3H_8[/tex] will give =[tex]\frac{3}{1}\times 4.6=13.8moles[/tex] of [tex]CO_2[/tex]
1 mole of [tex]C_3H_8[/tex] give = 4 moles of [tex]H_2O[/tex]
Thus 4.6 moles of [tex]C_3H_8[/tex] give =[tex]\frac{4}{1}\times 4.6=18.4moles[/tex] of [tex]H_2O[/tex]
Thus 13.8 moles of [tex]CO_2[/tex] and 18.4 moles of [tex]H_2O[/tex] will be produced from the given moles of reactant [tex]C_3H_8[/tex]
Why does a chemical change occur when copper is heated?
Answer:
When copper is heated, it decomposes to form copper oxide and carbon dioxide. It is an endothermic reaction, which means that it absorbs heat. When heated, copper is easily bent or molded into shapes.
Explanation:
A chemist prepares a solution of barium chlorate by measuring out of barium chlorate into a volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's barium chlorate solution. Be sure your answer has the correct number of significant digits.
Complete Question
A chemist prepares a solution of barium chlorate BaClO32 by measuring out 42.g of barium chlorate into a 500.mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in /molL of the chemist's barium chlorate solution. Be sure your answer has the correct number of significant digits.
Answer:
The concentration is [tex]C = 0.28 \ mol/L[/tex]
Explanation:
From the question we told that
The mass of [tex]Ba(ClO_{3})_2[/tex] is [tex]m_b = 42 \ g[/tex]
The volume of the solution [tex]V_s = 500 mL = 500*10^{-3} L[/tex]
Now the number f moles of [tex]Ba(ClO_{3})_2[/tex] in the solution is mathematically represented as
[tex]n = \frac{m_b}{Z_b}[/tex]
Where [tex]Z_b[/tex] is the molar mass of [tex]Ba(ClO_{3})_2[/tex] which a constant with a value
[tex]Z_b = 304.23 \ g/mol[/tex]
Thus
[tex]n = \frac{42}{304.23}[/tex]
[tex]n = 0.14 \ mol[/tex]
The concentration of [tex]Ba(ClO_{3})_2[/tex] in the solution is mathematically evaluated as
[tex]C = \frac{n}{V_2}[/tex]
substituting values
[tex]C = \frac{0.14}{500*10^{-3}}[/tex]
[tex]C = 0.28 \ mol/L[/tex]
Under certain conditions, the substances zinc oxide and water combine to form zinc hydroxide. If 30.1 grams of zinc oxide and 6.7 grams of water combine to form zinc hydroxide, how many grams of zinc hydroxide must form
Answer:
36.8g of Zinc hydroxide
Explanation:
Based on the reaction:
ZnO + H₂O → Zn(OH)₂
Where 1 mole of zinc oxide reacts with 1 mole of water to produce 1 mole of zinc hydroxide.
Moles of 30.1g of ZnO (FW = 81.38g/mol) are:
30.1g ZnO ₓ (1mol / 81.38g) = 0.370 moles of ZnO
And moles of 6.7g of H₂O (FW = 18.01g/mol) are:
6.7g H₂O ₓ (1mol / 18.01g) = 0.372 moles of H₂O
As 1 mole of ZnO reacts per mole of H₂O, limiting reactant is ZnO because has a less number of moles than water.
Thus, moles of Zn(OH)₂ produced are 0.370 moles.
As Molar mass of Zinc hydroxide is 99.424 g/mol, there are formed:
0.370 moles Zn(OH)₂ ₓ (99.424g / mol) =
36.8g of Zinc hydroxideWhat are the concentrations of Cu2+, NH3, and Cu(NH3)42+ at equilibrium when 18.8 g of Cu(NO3)2 is added to 1.0 L of a 0.800 M solution of aqueous ammonia? Assume that there is no volume change upon the addition of the solid, and that the reaction goes to completion and forms Cu(NH3)42+.
Answer:
Explanation:
Cu(NO₃)₂ + 4NH₃ = Cu(NH₃)₄²⁺ + 2 NO₃⁻
187.5 gm 4M 1 M
187.5 gm reacts with 4 M ammonia
18.8 g reacts with .4 M ammonia
ammonia remaining left after reaction
= .8 M - .4 M = .4 M .
187.5 gm reacts with 4 M ammonia to form 1 M Cu(NH₃)₄²⁺
18.8 g reacts with .4 M ammonia to form 0.1 M Cu(NH₃)₄²⁺
At equilibrium , the concentration of Cu²⁺ will be zero .
concentration of ammonia will be .4 M
concentration of Cu(NH₃)₄²⁺ formed will be 0.1 M
During the winter months, many locations experience snow and ice storms. It is a common practice to treat roadways and sidewalks with salt, such as NaCl . If a 11.3 kg bag of NaCl is used to treat the sidewalk, how many moles of NaCl does this bag contain
Answer:The moles of NaCL in the 11.3kg bag is 193.36moles
Explanation:
Given that a bag of NaCl = 11.3kg
1kg = 1000g
therefore 11.3 kg = 11,300g
Remember that
No of moles = mass of subatance/ molar mass of substance
The molar mass of NaCl = Na + Cl= 22.989769 + 35.453 =58.442769≈ 58.44g/mol
No of moles = mass of subatance/ molar mass of substance
= 11300g/ 58.44g/mol = 193.36 moles
The moles of NaCL in the 11.3kg bag is 193.36 moles.
When ethanol, C2H5OH (a component in some gasoline mixtures) is burned in air, one molecule of ethanol combines with three oxygen molecules to form two CO2 molecules and three H2O molecules.
A) Write the balanced chemical equation for the reaction described.
B) How many molecules of CO2 and H2O would be produced when 2 molecules ethanol are consumed? Equation?
C) How many H2O molecules are formed, then 9 O2 molecules are consumed? What conversion factor did you use? Explain!
D) If 15 ethanol molecules react, how many molecules O2 must also react? What conversion factor did you use? Explain!
Answer:
1) C2H5OH(l)+3O2(g)⟶2CO2(g)+3H2O(l)
2) four molecules of CO2 will be produced and six molecules of water
3)9 molecules of water are formed when 9 molecules of oxygen are consumed.
4) 45 molecules of oxygen
Explanation:
The balanced chemical reaction equation is shown here and must guide our work. When ethanol is burned in air, it reacts as shown;
C2H5OH(l)+3O2(g)⟶2CO2(g)+3H2O(l)
Hence, if we use 2 molecules of ethanol, the balanced reaction equation will look like this;
2C2H5OH(l)+6O2(g)⟶4CO2(g)+6H2O(l)
Hence four molecules of CO2 are formed and six molecules of water are formed
From the balanced stoichiometric equation;
3 molecules of oxygen yields 3 molecules of water
Therefore, 9 molecules of oxygen will yield 9 × 3/3 = 9 molecules of water
Therefore, 9 molecules of water are formed when 9 molecules of oxygen are consumed.
From the reaction equation;
1 molecule of ethanol reacts with 3 molecules of oxygen
Therefore 15 molecules of ethanol will react with 15 × 3/1 = 45 molecules of oxygen
Air is compressed from an inlet condition of 100 kPa, 300 K to an exit pressure of 1000 kPa by an internally reversible compressor. Determine the compressor power per unit mass flow rate if the device is (a) isentropic, (b) polytropic with n =1.3, (c) isothermal
Answer:
(a) [tex]W_{isoentropic}=8.125\frac{kJ}{mol}[/tex]
(b) [tex]W_{polytropic}=7.579\frac{kJ}{mol}[/tex]
(c) [tex]W_{isothermal}=5.743\frac{kJ}{mol}[/tex]
Explanation:
Hello,
(a) In this case, since entropy remains unchanged, the constant [tex]k[/tex] should be computed for air as an ideal gas by:
[tex]\frac{R}{Cp_{air}}=1-\frac{1}{k} \\\\\frac{8.314}{29.11} =1-\frac{1}{k}\\[/tex]
[tex]0.2856=1-\frac{1}{k}\\\\k=1.4[/tex]
Next, we compute the final temperature:
[tex]T_2=T_1(\frac{p_2}{p_1} )^{1-1/k}=300K(\frac{1000kPa}{100kPa} )^{1-1/1.4}=579.21K[/tex]
Thus, the work is computed by:
[tex]W_{isoentropic}=\frac{kR(T_2-T_1)}{k-1} =\frac{1.4*8.314\frac{J}{mol*K}(579.21K-300K)}{1.4-1}\\\\W_{isoentropic}=8.125\frac{kJ}{mol}[/tex]
(b) In this case, since [tex]n[/tex] is given, we compute the final temperature as well:
[tex]T_2=T_1(\frac{p_2}{p_1} )^{1-1/n}=300K(\frac{1000kPa}{100kPa} )^{1-1/1.3}=510.38K[/tex]
And the isentropic work:
[tex]W_{polytropic}=\frac{nR(T_2-T_1)}{n-1} =\frac{1.3*8.314\frac{J}{mol*K}(510.38-300K)}{1.3-1}\\\\W_{polytropic}=7.579\frac{kJ}{mol}[/tex]
(c) Finally, for isothermal, final temperature is not required as it could be computed as:
[tex]W_{isothermal}=RTln(\frac{p_2}{p_1} )=8.314\frac{J}{mol*K}*300K*ln(\frac{1000kPa}{100kPa} ) \\\\W_{isothermal}=5.743\frac{kJ}{mol}[/tex]
Regards.
Choose all that apply. According to the theory of matter proposed by John Dalton: all atoms of the same element have the same mass combinations of atoms create chemical change all matter is made up of atoms all atoms of the same element have the same size
Answer: all matter is made up of atoms
all atoms of the same element have the same mass combinations of atoms create chemical change
all atoms of the same element have the same size
Explanation:
Dalton's Atomic theory suggests that all matter are made up of atoms. All atoms are made up of same elements. The atoms of the same elements will have similar physical and chemical properties. The atoms will have same size, mass, and will show similar chemical changes. The atoms in the elements are indestructible blocks and indivisible.
how many grams are there in 9.4x10^25 molecules of H2
Answer:
You start with 9.4 x 1025 molecules of H2.
You know that an Avogadro's number of molecules of H2 has a mass of 2.0 g.
To solve, 9.4 x 1025 molecules H2 x (2.0 g H2 / 6.023 x 1023 molecules H2) = 312. g H2
Explanation:
A solution is prepared by dissolving 33.0 milligrams of sodium chloride in 1000. L of water. Assume a final volume of 1000. liters. Calculate the following values listed below.
a. Molarity of NaCl
b. Molarity of sodium ions
c. Molarity of chloride ions
d. Osmolarity of the solution
e. Mass percent of NaCl
f. Parts per million of sodium chloride
g. Parts per billion of sodium chloride
h. Look at your answers to parts e, f, and g.
Which one of these values is the most convenient or easiest to say and use/understand when discussing concentration.
Answer:
a. Molarity of NaCl solution = 5.64 * 10⁻⁷ mol/L
b. molarity of Na⁺ = 5.64 * 10⁻⁷ mol/L
c. molarity of Cl⁻ = 5.64 * 10⁻⁷ mol/L
d. Osmolarity = 1.128 osmol
e. mass percent of NaCl = 3.30 * 10⁻⁶ %
f. parts per million NaCl = 0.033 ppm NaCl
g. parts per billion of NaCl = 33 ppb of NaCl
h. From the values obtained from e, f and g, the most convenient to use and understand is parts per billion as it has less of a fractional part to deal with especially since the solute concentration is very small.
Explanation:
Molarity of a solution = number of moles of solute (moles)/volume of solution (L)
where number of moles of solute = mass of solute (g)/molar mass of solute (g/mol)
a. Molarity of NaCl:
molar mass of NaCl = 58.5 g/mol, mass of NaCl = 33.0/1000) g = 0.033g
number of moles of NaCl = 0.033/58.5 = 0.000564 moles
Molarity of NaCl solution = 0.000564/1000 = 5.64 * 10⁻⁷ mol/L
b. Equation for the dissociation of NaCl in solution: NaCl ----> Na⁺ + Cl⁻
From the above equation I mole of NaCl dissociates to give 1 mole of Na⁺ ions,
Therefore molarity of Na⁺ = 1 * 5.64 * 10⁻⁷ mol/L = 5.64 * 10⁻⁷ mol/L
c. From the above equation I mole of NaCl dissociates to give 1 mole of Cl⁻ ions,
therefore molarity of Cl⁻ = 1 * 5.64 * 10⁻⁷ mol/L = 5.64 * 10⁻⁷ mol/L
d. From the above equation, dissociation of NaCl in water produces 1 mol Na⁺ and 1 mole Cl⁻.
Total number of particles produced = 2
Osmolarity of solution = number of particles * molarity of siolution
Osmolarity = 2 * 5.64 * 10⁻⁷ mol/L = 1.128 osmol
e. mass of percent of NaCl = {mass of NaCl (g)/ mass of solution (g)} * 100
density of water = 1 Kg/L
mass of water = 1 Kg/L * 1000 L = 1000 kg
1Kg = 1000 g
Therefore mass of solution in g = 1000 * 1000 = 1 * 10⁶ g
mass percent of NaCl = (0.033/1 * 10⁶) * 100 = 3.30 * 10⁻⁶ %
f. Parts per million of NaCl:
parts per million = 1 mg of solute/L of solution
One thousandth of a gram is one milligram and 1000 ml is one liter, so that 1 ppm = 1 mg per liter = mg/Liter.
Since the density of water is 1kg/L = 1,000,000 mg/L
1mg/L = 1mg/1,000,000mg or one part in one million.
parts per million NaCl = 33.0/1000 L = 0.033 ppm NaCl
g. Parts per billion = 1 µg/L of solution
1 g = 1000 µg
therefore, 33.0 mg = 33.0 * 1000 µg = 3.30 * 10⁴ µg
parts per billion of NaCl = 3.30 * 10⁴ µg/1000 L = 33 ppb of NaCl
h. From the values obtained from e, f and g, the most convenient to use and understand is parts per billion as it has less of a fractional part to deal with especially since the solute concentration is very small.
Determine the quantity (g) of pure MgSO4 in 2.4 g of MgSO4•7H2O. Show your work.
Answer: The quantity of pure [tex]MgSO_4[/tex] in 2.4 g of [tex]MgSO_4.7H_2O[/tex] is 1.17 g
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar Mass}}=\frac{2.4g}{246g/mol}=0.0098moles[/tex]
As 1 mole of [tex]MgSO_4.7H_2O[/tex] contains = 1 mole of [tex]MgSO_4[/tex]
Thus 0.0098 moles of [tex]MgSO_4.7H_2O[/tex] contains = [tex]\frac{1}{1}\times 0.0098=0.0098mole[/tex] of [tex]MgSO_4[/tex]
Mass of [tex]MgSO_4=0.0098mol\times 120g/mol=1.17g[/tex]
Thus the quantity of pure [tex]MgSO_4[/tex] in 2.4 g of [tex]MgSO_4.7H_2O[/tex] is 1.17 g
How many grams of POCl3 are produced when 225.0 grams of P4O10 and 675.0 grams of PCl5 react? This is the balance equation P4O10 + 6PCl5 → 10POCl3
Answer:
900g of POCl₃
Explanation:
Hello,
To solve this question, we'll require the equation of reaction.
P₄O₁₀ + 6PCl₅ → 10POCl₃
Molar mass of P₄O₁₀ = 283.886 g/mol
Molar mass of PCl₅ = 208.24 g/mol
Molar mass of POCl₃ = 153.33 g/mol
But Number of moles = mass / molar mass
Mass = molar mass × number of moles
Mass of POCl₃ = 153.33 × 10 = 1533.3g
Mass of PCl₅ = 208.24 × 6 = 1249.44g
Mass of P₄O₁₀ = 283.886 × 1 = 283.886g
From the equation of reaction,
283.886g of P₄O₁₀ + 1249.44g of PCl₅ produces 1533.33g of POCl₃
I.e 1533.33g of reactants produces 1533.33g of product (law of conservation of mass)
Therefore, (225g of P₄O₁₀ + 675g of PCl₅) = 900g will give x g of POCl₃.
1533.33g of reactants = 1533.33g of products
900g of reactants = x g of products
x = (900 × 1533.33) / 1533.33
x = 900g of POCl₃