Answer:
1.2×10² mmole of Na₂S₂O₃
Explanation:
From the question given above, the following data were obtained:
Volume = 0.6 L
Molarity = 0.2 mol/L
Mole of Na₂S₂O₃ =?
Molarity is simply defined as the mole of solute per unit litre of water. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the number of mole of Na₂S₂O₃ in the solution as illustrated below:
Volume = 0.6 L
Molarity = 0.2 mol/L
Mole of Na₂S₂O₃ =?
Molarity = mole /Volume
0.2 = Mole of Na₂S₂O₃ / 0.6
Cross multiply
Mole of Na₂S₂O₃ = 0.2 × 0.6
Mole of Na₂S₂O₃ = 0.12 mole
Finally, we shall convert 0.12 mole to millimole (mmol). This can be obtained as follow:
1 mole = 1000 mmol
Therefore,
0.12 mole = 0.12 mole × 1000 mmol / 1 mole
0.12 mole = 120 = 1.2×10² mmole
Thus, the chemist added 1.2×10² mmole of Na₂S₂O₃
The heat of vaporization of water at the normal boiling point, 373.2 K, is 40.66 kJ/mol. The molar heat capacity of liquid water is 75.37 J K-1 mol-1 and that of gaseous water is 36.4 J K-1 mol-1. Assume that these values are independent of temperature. What is the heat of vaporization of water at 300.2 K?
Answer:
[tex]\Delta _{vap}H(300.2K)=43,658\frac{J}{mol}=43.66\frac{kJ}{mol}[/tex]
Explanation:
Hello!
In this case, according to the Kirchhoff's law for the enthalpy change, it is possible to compute the heat of vaporization at 300.2 K by considering the following thermodynamic route:
[tex]\Delta _{vap}H(300.2K)=Cp_{liq}(T_b-T\°)+\Delta _{vap}H\°+Cp_{vap}(T-T_B)[/tex]
Whereas the first term stands for the effect of taking the liquid from 298.15 K to 373.15 K, the second term stands for the standard enthalpy of vaporization and the last term that of the vapor from the boiling point to 300.2 K; thus we plug in to obtain:
[tex]\Delta _{vap}H(300.2K)=75.37\frac{J}{mol*K} (373.2K-298.15K)+40,660\frac{J}{mol} +36.4\frac{J}{mol*K}(300.2K-373.2K)\\\\\Delta _{vap}H(300.2K)=43,658\frac{J}{mol}=43.66\frac{kJ}{mol}[/tex]
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A 1.018 g sample pure platinum metal was reacted with HCl to form 1.778 g of a compound containing only platinum and chlorine. What is the percent by mass of platinum?
Answer:
57.26 %
Explanation:
Step 1: Write the balanced equation
Pt + 2 HCl ⇒ PtCl₂ + H₂
Step 2: Calculate the mass of Pt in 1.778 g of PtCl₂
According to the law of conservation of the mass, all the mass of Pt in the reactants must be present in the products. Since PtCl₂ is the only product that contains Pt, the mass of Pt is 1.018 g
Step 3: Calculate the percent by mass of platinum in PtCl₂
We will use the following expression.
%Pt = mPt / mPtCl₂ × 100%
%Pt = 1.018 g / 1.778 g × 100% = 57.26 %
What is the total amount of heat released in kilojoules when 112.0 g water at 50.0∘C cools to form ice at −45.0∘C? Use the following values for calculations, as needed.
Properties of Water−−−−−−−−−−−−−−−−−−Specific Heats(∘C)gas=1.84 J/g∘Cliquid=4.184 J/g∘Csolid=2.09 J/g∘C
Heat of VaporizationΔHvap=40.7 kJ/molHeat of FusionΔHfus=6.01 kJ/mol
Answer:
Q = 44.5 kJ
Explanation:
Given that,
Mass of water, m = 112 g
Water at 50.0°C cools to form ice at −45.0°C
We need to find the total amount of heat released. The formula for heat released is given by :
[tex]Q=mc\Delta T[/tex]
c is the specific heat of water, c = 4.184 J/g°C
So,
[tex]Q=112\times 4.184 \times (-45-50)\\\\Q=-44517.76\ J[/tex]
or
Q = -44.5 kJ
So, 44.5 kJ of heat is released.
A 1.0 mol sample of he(g) at 25 is mixed with a 1.0 mol sample of Xe(g) at 50 C. What would be the changes in average kineeteic energy and the average speed of the Xe atoms that will occur as the mixture approaches thermal equilibrium?
Answer:
Explanation:
The average kinetic energy for an ideal gas is directly proportional to the temperature. The average kinetic energy of the gas is a measure of the temperature of the gas molecule
Also, the average speed is usually proportional to the square root of temperature.
Similarly, there is a noticeable increase in K.E and speed in regard to temperature but sometimes it is not usually proportional.
However, provided that there is more temperature in Xe as compared to He, then after the mixture of both takes place at equilibrium; the temperature tends to fluctuate between (25 - 50)°C
Thus, since there is a decrease in temperature in Xe, both the average kinetic energy as well as the speed too will also decrease.
identify the equipment best suited for extinguishing each type of fire. Your choices are: fire extinguisher, overturned beaker, fire blanket.
Answer: The equipment best suited for extinguishing each type of fire are listed below:
--> Fire extinguisher: Large fire on the floor
--> Overturned beaker: Small benchtop fire
--> Fire blanket: clothing fire.
Explanation:
Fire outbreaks is a common event that can be prevented in a standard chemistry laboratory with the aid of fire safety equipments.
The method used by these equipments to extinguish fire is to suffocate the fire by obstructing the source of oxygen, by reducing the heat with the use of water and removing the fuel or oxygen source.
These fire safety equipments should be highly visible and easily accessible in a laboratory. Example of fire safety equipments includes:
--> Fire extinguisher: A laboratory personnel needs to be trained in the use of this since it's made up of different types. it can be used to extinguish ( put out) large fire on the floor.
--> Overturned beaker: this can be used to suffocate small fire on the bench which is also common in the laboratory.
-->Fire blanket: This should be used in the event that a person’s body or clothing catches fire.
As the temperature of a substance increases, the average___________ energy of the particles also increases, and movement overcomes forces of ________ more easily. As temperature decreases particles move more slowly and the_________ forces between particles dominate.
Answer:
Kinetic; attraction; attraction.
Explanation:
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}MV^{2}[/tex]
Where, K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.
In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.
Hence, as the temperature of a substance increases, the average kinetic energy of the particles also increases, and movement overcomes forces of attraction more easily. As temperature decreases particles move more slowly and the attraction-forces between particles dominate.
In conclusion, when a substance or an object is heated, a phase change starts to occur only when the average kinetic energy of its particles is great enough to overcome the force of attraction between its particles.
How can the IR spectrum be used to show that there is not starting material left and the products are alcohols
Answer:
hello your question is incomplete attached below is the complete question
answer :
Absence of c = c = C-H of the peak and the presence of -O-H and C-O peak shows that there is presence of Alcohols as products and it also shows that there is no starting material left
Explanation:
To provide that there is no starting material left and products are alcohols using the IR spectrum we will apply hydroboration oxidation
Absence of c = c = C-H of the peak and the presence of -O-H and C-O peak shows that there is presence of Alcohols as products and it also shows that there is no starting material left
attached below is the detailed solution
What is the mass of 3.00 -1023 particles of water? Water has a molar mass of 18.0 g/mol.
3.00 grams
18.0 grams
6.00 grams
9.00 grams
Answer:
bro
Explanation:
guhfuyfouyvyu
Answer:
9.00
Explanation:
I took the test and got it correct ...
What is the value of 4.698 after rounding it down to 3 significant figures?
Every morning, Jeremiah uses a blender to make a smoothie for breakfast. Which of the
following shows the energy transformation that the blender demonstrates?
А
Electrical - light
B
Chemical → mechanical
с
Mechanical → chemical
D
Electrical mechanical
Answer:
D
Explanation:
Answer:
D: Electrical -> mechanical
Explanation:
Hope this helps!
a sample of fully saturated clay weighs 1350 g in its natural state and 975 g after drying. what is the natural water content of the soil
Answer:
The soil has a percentage of water by mass of 27.8 %.
Explanation:
Keeping in mind that
Mass of Clay = Mass of water + Mass of Dry Soilwe can calculate the mass of water:
1350 g = Mass of Water + 975 gMass of Water = 375 gWe can then calculate the mass percentage of water in the soil:
375 / 1350 * 100% = 27.8 %Based on the following chemical equation how many molecules of Hydrogen (H) are present in the reactants side?
2H2 + O2 ----> 2H2O
Question 1 options:
1
2
3
4
Answer:
2
Explanation:
Based on the chemical equation, the number of molecules of hydrogen gas in the reactant side is 2.
This is indicated by the coefficient before reactant.
A molecule is a covalent compound that has discrete or separate units.
So H₂ is made up of two atoms of hydrogen that has been covalently bonded together by sharing their valence electrons.
From the reaction expression:
2 molecules of hydrogen gas combines with 1 molecule of oxygen gas to produce 2 molecules of water.
You want to compare the malleability of
two metals. Plan an investigation that would allow you to determine
which metal is more malleable .
The temperature and the strength of the metallic link are the two most crucial variables that can impact how malleable a metal or alloy is.
What is metal ?A metal is a substance that has a shiny look when freshly processed, polished, or shattered, and conducts electricity and heat rather effectively. Generally speaking, metals are malleable and ductile.
The amount of pressure that a metal can sustain without breaking can be used to gauge its malleability. Varied metals have different degrees of malleability because of variations in their crystal structures.
The temperature of the metal and the strength of the metallic connection are the two parameters that define how malleable a metal or metal alloy will be.
Thus, The kind of the metallic connection can have a significant impact on how easily metal atoms can rearrange themselves.
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A compound is made of 6.00 grams of oxygen, 7.00 grams of nitrogen, and 20.00grams of hydrogen. Find the percent composition of the compound.
A O-18.18%, N-21.21%, H-60.60%
B O-11.18%, N-22.21%, H-69.60%
C O-20%, N-30%, H-50%
D O-60.60%, N-21.21%, H-18.18%
The percent composition of the compound.
A O-18.18%, N-21.21%, H-60.60%
Further explanationGiven
6.00 grams of oxygen,
7.00 grams of nitrogen,
20.00 grams of hydrogen.
Required
The percent composition
Solution
Total mass :
= mass of O + mass of N + mass of H
= 6 + 7 + 20
= 33 g
% O = 6/33 x 100%= 18.18%
% N = 7/33 x 100%=21.21%
% H = 20/33 x 100% = 60.6 %
A quantity of water is heated from 25.0°C to 36.4°C by absorbing 325 J of heat energy. If the specific heat of water is 4.18 J / g°C, what mass is this quantity of water?
Answer:
6,8 g
Explanation:
c = 4.18 J/(g * °C) = 4180 J / (kg * °C)
[tex]t_{1}[/tex] = 25 °C
[tex]t_{2}[/tex] = 36,4 °C
Q = 325 J
The formula is: Q = c * m * ([tex]t_{2} - t_{1}[/tex])
m = [tex]\frac{Q}{c * (t_{2} - t_{1} )}[/tex]
Calculating:
m = 325 / 4180 * (36,4 - 25) ≈ 0,0068 kg = 6,8 g
The mass of the quantity of water heated from 25.0°C to 36.4°C by absorbing 325 J of heat energy is 6.8grams.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by using the following formula:
Q = m × c × ∆T
Where;
Q = quantity of heat absorbed (J)c = specific heat capacity (4.18 J/g°C)m = mass of substance∆T = change in temperature (°C)According to this question;
m = ?
∆T = 36.4°C - 25°C = 11.4°C
Q = 325J
325 = m × 4.18 × 11.4
325 = 47.65m
m = 325 ÷ 47.65
m = 6.8g
Therefore, the mass of the quantity of water heated from 25.0°C to 36.4°C by absorbing 325 J of heat energy is 6.8grams.
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How many cm 3 are in 0.014 in 3? (1 in = 2.54 cm)
Answer:
0.229 cm³.
Explanation:
The following data were obtained from the question:
Volume (in in³) = 0.014 in³
Volume (in cm³) =?
1 in = 2.54 cm
Next, we shall determine a conversion scale to convert from in³ to cm³. This can be obtained as follow:
1 in = 2.54 cm
Therefore,
1 in³ = 2.54³ cm³
1 in³ = 16.387 cm³
Finally, we shall convert 0.014 in³ to cm³. This can be obtained as follow:
1 in³ = 16.387 cm³
Therefore,
0.014 in³ = 0.014 in³ × 16.387 cm³ / 1 in³
0.014 in³ = 0.229 cm³
Thus, 0.014 in³ is equivalent to 0.229 cm³.
How many molecules are there in 0.75 mol NH3
There are 4.5165 × 10²³ molecules are there in 0.75 mol NH₃.
A molecule is a set of or more atoms held together by means of attractive forces referred to as chemical bonds; depending on the context, the term may additionally or won't encompass ions that satisfy this criterion.
1 mole of NH₃ = 6.022 × 10²³
0.75 mole = 6.022 × 10²³ × 0.75 molecule
= 4.5165 × 10²³ molecules.
A molecule is defined as the smallest unit of a compound that consists of the chemical properties of the compound. Molecules are made of agencies of atoms. Describing the shape of an atom, an atom is also subdivided into smaller devices. Protons, electrons, and neutrons are sub-debris of an atom. The smallest particle of a substance has all of the bodily and chemical homes of that substance. Molecules are made up of 1 or extra atoms.
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How many formula units are contained in 0.57 g Cao?
The ozone "hole" over Antarctica formed as the result of a series of chemical reactions. The loss occurs in part through three consecutive steps in which ozone is broken down: Step 1: Chlorine atoms react with ozone (O3) to form chlorine monoxide and molecular oxygen. Step 2: Chlorine monoxide molecules combine to form ClOOCl gas Step 3: ClOOCl absorbs sunlight and breaks into chlorine atoms and molecular oxygen. a) Write a balanced equation for each step. b) Write an overall balanced equation for the sequence
Answer:
A)
Cl + O3 --> ClO + O2
2ClO --> ClOOCl
ClOOCl --> 2 Cl + O2
B)
Cl2 + 4O3 -> 2 ClO + 5O2
Explanation:
Step 1: Chlorine atoms react with ozone (O3) to form chlorine monoxide and molecular oxygen
Cl + O3 --> ClO + O2
Step 2: Chlorine monoxide molecules combine to form ClOOCl gas
2ClO --> ClOOCl
Step 3: ClOOCl absorbs sunlight and breaks into chlorine atoms and molecular oxygen
ClOOCl --> 2 Cl + O2
B) Overall Balanced equation
Cl2 + 4O3 -> 2 ClO + 5O2
Of the three layers of the biosphere, which one is inhabited by jellyfish?
Answer:
Hydrosphere
Explanation:
The biosphere simply refers to the zone of life found on earth. It refers to the portion of the earth inhabited by living things.
The biosphere is divided into three, namely; hydrosphere, atmosphere and lithosphere.
The atmosphere is simply the layer composed of air, the lithosphere is the solid part of the earth while the hydrosphere is the part composed of water.
Since jelly fish is an aquatic animal, it will certainly inhabit the hydrosphere. Hence the answer above.
A chemist prepares a solution of aluminum sulfate by weighing out of aluminum sulfate into a volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's aluminum sulfate solution. Be sure your answer has the correct number of significant digits.
Answer:
25.8 g/dL
Explanation:
A chemist prepares a solution of aluminum sulfate by weighing out 116.0 g of aluminum sulfate into a 450. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in g/dL of the chemist's aluminum sulfate solution. Be sure your answer has the correct number of significant digits.
Step 1: Given data
Mass of aluminum sulfate (m): 116.0 gVolume of the solution (V): 450. mLStep 2: Convert "V" to dL
We will use the following conversion factors.
1 L = 1000 mL1 L = 10 dL450. mL × 1 L/1000 mL × 10 dL/1 L = 4.50 dL
Step 3: Calculate the concentration (C) of aluminum sulfate if g/dL
We will use the following expression.
C = m/V = 116.0 g/4.50 dL = 25.8 g/dL
What are the non-living things that make up an ecosystem?
Answer:
abiotic things
abiotic things aren't living
Answer:
The non-living things would be the soil, rocks, and water. There are other things, but those are the main ones.
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How many grams of hydrogen gas will be produced if you start with 15.0 grams of zinc and an excess amount of HCI?
balanced equation:
Zn + 2HCI = ZnCl2 + H2
Answer:
0.48g
Explanation:
Given parameters:
Mass of zinc = 15g
Unknown:
Mass of hydrogen gas = ?
Solution:
To solve this problem, we need to state the balanced reaction expression first;
Zn + 2HCl → ZnCl₂ + H₂
Find the number of moles of Zn;
Number of moles = [tex]\frac{mass}{molar mass}[/tex] = [tex]\frac{15}{63.4}[/tex] = 0.24mol
From the balanced reaction expression;
1 mole of Zn will produce 1 mole of H₂
0.24mole of Zn will produce 0.24mole of hydrogen gas
Mass of hydrogen gas = number of moles x molar mass
= 0.24 x (2 x 1)
= 0.48g
Indium has a tetragonal unit cell for which the a and c lattice parameters are 0.459 and 0.495 nm, respectively. (a) If the atomic packing factor and atomic radius are 0.693 and 0.1625 nm, respectively, determine the number of atoms in each unit cell. (b) The atomic weight of indium is 114.82 g/mol; compute its theoretical density. (a) Enter your answer for part (a) in accordance to the question statement atoms/unit cell (b) Enter your answer for part (b) in accordance to the question statement g/cm3
Answer:
A) 4 atoms/unit cell
B) 7.31 g/cm^3
Explanation:
A) Determine the number of atoms in each unit cell
attached below is the detailed solution
number of atoms per unit cell ( n ) = 4 atoms/unit cell
B) Given atomic weight of indium = 114.82 g/mol
hence the theoretical density = 7.31 g/cm^3
Attached below is a detailed solution of the question
Which is an example of maintaining structure?
Question 4 options:
healing a wound
sweating
all answers are examples of maintaining structure
keep from getting too cold
Answer: healing a wound
Explanation:
The healing of the wound is the example of maintenance of the structure. The wound is the injury which disturbs the continuity of the skin surface. It can affect the dermal and epidermal layer of the skin. The wound if severe or deep can damage the bones. The wound can be caused by the cut, blow or punch, impact or fall from height. The healing of the wound may take several days to weeks. The wound healing involves the replacement of the damaged or destroyed cells or tissues by new cells or tissues in the body or the wound site.
if a molecular formula is C8H12O2, what is the empirical formula
Answer:
C₄ H₆ O
Explanation:
The molecular formula of the compound is given as:
C₈ H₁₂ O₂
The molecular formula of a compound is expresses the true number of atoms within a compound.
The empirical formula gives the simplest ratio of the atoms within a compound.
Elements C H O
Number of atoms 8 12 2
Divide through by a
Common factor 8/2 12/2 2/2
4 6 1
The empirical formula therefore is C₄ H₆ O
Graciella divided her grapes equally among 6 friends. If each friend received 16 grapes how many grapes did Graciella have?
Answer: She had 96 grapes.
Explanation:
Answer:
taiks
Explanation:
The total thermal energy of a system depends jointly on the temperature, total number of in the system _______________, and the _______________of the material. *
1. Molecules/State
2. Molecules/Heat
3. Matter/Heat
4. Atoms/State
Answer:
Molecules/State
Explanation:
We know from the kinetic molecular theory that matter is made up of molecules. These molecules are in constant motion at various velocities and energies.
The total thermal energy refers to the total kinetic energies of these particles. It depends on the temperature of the system, the energies of the molecules present in the material and the arrangement of the object's molecules (states of matter).
When 70.4 g of benzamide (C7H7NO) are dissolved in 850. g of a certain mystery liquid X, the freezing point of the solution is 2.7 C lower than the freezing point of pure X. On the other hand, when 70.4 g of ammonium chloride (NH CI) are dissolved in the same mass of X, the freezing point of the solution is 9.9 °C lower than the freezing point of pure X.
Required:
Calculate the van't Hoff factor for ammonium chloride in X.
Answer:
1.62
Explanation:
From the given information:
number of moles of benzamide [tex]=\dfrac{70.4 \ g}{121.14 \ g/mol}[/tex]
= 0.58 mole
The molality = [tex]\dfrac{mass \ of \ solute (i.e. \ benzamide )}{mass \ of \ solvent }[/tex]
[tex]= \dfrac{0.58 }{0.85 }[/tex]
= 0.6837
Using the formula:
[tex]\mathbf {dT = l \times k_f \times m}[/tex]
where;
dT = freezing point = 27
l = Van't Hoff factor = 1
kf = freezing constant of the solvent
∴
2.7 °C = 1 × kf × 0.6837 m
kf = 2.7 °C/ 0.6837m
kf = 3.949 °C/m
number of moles of NH4Cl = [tex]\dfrac{70.4 \ g}{53.491 \ g /mol}[/tex]
= 1.316 mol
The molality = [tex]\dfrac{1.316 \ mol}{0.85 \ kg}[/tex]
= 1.5484
Thus;
the above kf value is used in determining the Van't Hoff factor for NH4Cl
i.e.
9.9 = l × 3.949 × 1.5484 m
[tex]l = \dfrac{9.9}{3.949 \times 1.5484 \ m}[/tex]
l = 1.62
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1. Jimmy picks up a 5kg box and places it on a shelf 1 meter from the ground. What is the
gravitational potential energy of the box?
Answer: 49 joules
Explanation: gravitational potential energy = mgh
m= mass kg, g= acceleration due to gravity 9.8 m/sec/sec, h= height m
=5*9.8.1 joules = 49 joules