Question 1

Calculate the volume occupied by 35.2 g of methane gas (CH4)at 25°C and 1.0 atm.R = 0.08206 L.atm/K.mol.

Accepted Answer

A) 0.0186 L 
B) 4.5 L 
C) 11.2 L 
D) 49.2 L 
E) 53.7 L 
A) 0.0186 L 
B) 4.5 L 
C) 11.2 L 
D) 49.2 L 
E) 53.7 L

Question 2

What is V in the table below?

Accepted Answer

The answer of What is V in the table below?...

Question 3

Packaged cake mixes usually contain baking powder, a mixture of sodium hydrogen carbonate and calcium hydrogen phosphate that react to produce carbon dioxide gas when they are heated in water.The CO2(g)formed allows the cake to "rise." When such cake mixes are used at high altitudes, often the cake will rise too much and collapse, unless special instructions are followed.Why does this happen?

Accepted Answer

Due to the reduced a

Question 4

A sample of N2 gas occupies 2.40 L at 20°C. If the gas is in a container that can contract or expand at constant pressure, at what temperature will the N2 occupy 4.80 L?

Accepted Answer

A) 10°C 
B) 40°C 
C) 146°C 
D) 313°C 
E) 685°C 
A) 10°C 
B) 40°C 
C) 146°C 
D) 313°C 
E) 685°C

Question 5

A convenient way to produce very high purity oxygen in the laboratory is to decompose KMnO4(s)at high temperature according to the following chemical equation:
2KMnO4(s)$\rarr$ K2MnO4(s)+ MnO2(s)+ O2(g)
If 2.50 L of O2(g)is needed at 1.00 atm and 20°C, what mass of KMnO4(s)should be decomposed? Assume the decomposition of KMnO4(s)goes to completion.

Accepted Answer

The answer of A convenient way to produce very high...

Question 6

At standard temperature and pressure, a given sample of water vapor occupies a volume of 2.80 L. How many moles of water vapor are present?

Accepted Answer

The answer of At standard temperature and pressure, a given...

Question 7

Air contains 78% N2, 21% O2, and 1% Ar, by volume. What is the density of air at 1,000.torr and -10°C?

Accepted Answer

A) 1.0 g/L 
B) 6.1 g/L 
C) 1.3 g/L 
D) 1.8 g/L 
E) 0.56 g/L 
A) 1.0 g/L 
B) 6.1 g/L 
C) 1.3 g/L 
D) 1.8 g/L 
E) 0.56 g/L

Question 8

What volume of CO2 gas at 645 torr and 800 K could be produced by the reaction of 45 g of CaCO3 according to the equation? CaCO3(s)$\rarr$CaO(s)+ CO2(g)

Accepted Answer

A) 0.449 L 
B) 22.4 L 
C) 25.0 L 
D) 34.8 L 
E) 45.7 mL 
A) 0.449 L 
B) 22.4 L 
C) 25.0 L 
D) 34.8 L 
E) 45.7 mL

Question 9

Calculate the volume of H2(g)at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

Accepted Answer

A) 0.56 L 
B) 1.12 L 
C) 2.23 L 
D) 4.47 L 
E) 3.54 L 
A) 0.56 L 
B) 1.12 L 
C) 2.23 L 
D) 4.47 L 
E) 3.54 L

Question 10

Phosgene, a chemical warfare agent used in World War I, consists of 12.41% C, 16.17% O, and 71.69% Cl.1.00 L of this gas at STP has a mass of 4.42 g. What is the molecular formula of phosgene?

Accepted Answer

The answer of Phosgene, a chemical warfare agent used in...

Question 11

A small bubble rises from the bottom of a lake, where the temperature and pressure are 4°C and 3.0 atm, to the water's surface, where the temperature is 25°C and the pressure is 0.95 atm.Calculate the final volume of the bubble if its initial volume was 2.1 mL.

Accepted Answer

A) 0.72 mL 
B) 6.2 mL 
C) 41.4 mL 
D) 22.4 mL 
E) 7.1 mL 
A) 0.72 mL 
B) 6.2 mL 
C) 41.4 mL 
D) 22.4 mL 
E) 7.1 mL

Question 12

A pressure that will support a column of Hg to a height of 256 mm would support a column of water to what height? The density of mercury is 13.6 g/cm3; the density of water is 1.00 g/cm3.

Accepted Answer

A) 1.00 * 102 ft 
B) 18.8 mm 
C) 33.8 ft 
D) 76.0 cm 
E) 348 cm 
A) 1.00 * 102 ft 
B) 18.8 mm 
C) 33.8 ft 
D) 76.0 cm 
E) 348 cm

Question 13

If the pressure of a gas sample is quadrupled and the absolute temperature is doubled, by what factor does the volume of the sample change?

Accepted Answer

A) 8 
B) 2 
C) 1/2 
D) 1/4 
E) 1/8 
A) 8 
B) 2 
C) 1/2 
D) 1/4 
E) 1/8

Question 14

A sample of carbon monoxide gas was collected in a 2.0 L flask by displacing water at 28°C and 810 mmHg. Calculate the number of CO molecules in the flask. The vapor pressure of water at 28°C is 28.3 mmHg.

Accepted Answer

A) 5.0 * 1022 
B) 5.2 * 1022 
C) 3.8 * 1023 
D) 5.4 * 1023 
E) 3.8 * 1025 
A) 5.0 * 1022 
B) 5.2 * 1022 
C) 3.8 * 1023 
D) 5.4 * 1023 
E) 3.8 * 1025

Question 15

Which of these gases will have the greatest density at the same specified temperature and pressure?

Accepted Answer

A) H2 
B) CClF3 
C) CO2 
D) C2H6 
E) CF4 
A) H2 
B) CClF3 
C) CO2 
D) C2H6 
E) CF4

Question 16

A 2.50-L flask contains a mixture of methane (CH4)and propane (C3H8)at a pressure of 1.45 atm and 20°C. When this gas mixture is then burned in excess oxygen, 8.60 g of carbon dioxide is formed. (The other product is water.)What is the mole fraction of methane in the original gas mixture?

Accepted Answer

A) 0.341 
B) 1.00 
C) 0.659 
D) 0.855 
E) 0.145 
A) 0.341 
B) 1.00 
C) 0.659 
D) 0.855 
E) 0.145

Question 17

Which of these gas molecules have the highest average kinetic energy at 25°C?

Accepted Answer

A) H2 
B) O2 
C) N2 
D) Cl2 
E) All the gases have the same average kinetic energy. 
A) H2 
B) O2 
C) N2 
D) Cl2 
E) All the gases have the same average kinetic energy.

Question 18

What is the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 720 mmHg?

Accepted Answer

A) 12 mmHg 
B) 708 mmHg 
C) 720 mmHg 
D) 732 mmHg 
E) 760 mmHg 
A) 12 mmHg 
B) 708 mmHg 
C) 720 mmHg 
D) 732 mmHg 
E) 760 mmHg

Question 19

A 1.17 g sample of an alkane hydrocarbon gas occupies a volume of 674 mL at 28°C and 741 mmHg.Alkanes are known to have the general formula CnH2n+2.What is the molecular formula of the gas in this sample? (R = 0.08206 L.atm/K.mol)

Accepted Answer

A) CH4 
B) C2H6 
C) C3H8 
D) C4H10 
E) C5H12 
A) CH4 
B) C2H6 
C) C3H8 
D) C4H10 
E) C5H12

Question 20

A gaseous compound is 30.4% nitrogen and 69.6% oxygen by mass. A 5.25-g sample of the gas occupies a volume of 1.00 L and exerts a pressure of 1.26 atm at -4.0°C. Which of these choices is its molecular formula?

Accepted Answer

A) NO 
B) NO2 
C) N3O6 
D) N2O4 
E) N2O5 
A) NO 
B) NO2 
C) N3O6 
D) N2O4 
E) N2O5

Exam 5: Gases

Calculate the volume occupied by 35.2 g of methane gas (CH4)at 25°C and 1.0 atm.R = 0.08206 L.atm/K.mol.

What is V in the table below?

A sample of N2 gas occupies 2.40 L at 20°C. If the gas is in a container that can contract or expand at constant pressure, at what temperature will the N2 occupy 4.80 L?

At standard temperature and pressure, a given sample of water vapor occupies a volume of 2.80 L. How many moles of water vapor are present?

Air contains 78% N2, 21% O2, and 1% Ar, by volume. What is the density of air at 1,000.torr and -10°C?

What volume of CO2 gas at 645 torr and 800 K could be produced by the reaction of 45 g of CaCO3 according to the equation? CaCO3(s) →\rarr→ CaO(s)+ CO2(g)

Calculate the volume of H2(g)at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

Phosgene, a chemical warfare agent used in World War I, consists of 12.41% C, 16.17% O, and 71.69% Cl.1.00 L of this gas at STP has a mass of 4.42 g. What is the molecular formula of phosgene?

A small bubble rises from the bottom of a lake, where the temperature and pressure are 4°C and 3.0 atm, to the water's surface, where the temperature is 25°C and the pressure is 0.95 atm.Calculate the final volume of the bubble if its initial volume was 2.1 mL.

A pressure that will support a column of Hg to a height of 256 mm would support a column of water to what height? The density of mercury is 13.6 g/cm3; the density of water is 1.00 g/cm3.

If the pressure of a gas sample is quadrupled and the absolute temperature is doubled, by what factor does the volume of the sample change?

A sample of carbon monoxide gas was collected in a 2.0 L flask by displacing water at 28°C and 810 mmHg. Calculate the number of CO molecules in the flask. The vapor pressure of water at 28°C is 28.3 mmHg.

Which of these gases will have the greatest density at the same specified temperature and pressure?

A 2.50-L flask contains a mixture of methane (CH4)and propane (C3H8)at a pressure of 1.45 atm and 20°C. When this gas mixture is then burned in excess oxygen, 8.60 g of carbon dioxide is formed. (The other product is water.)What is the mole fraction of methane in the original gas mixture?

Which of these gas molecules have the highest average kinetic energy at 25°C?

What is the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 720 mmHg?

A 1.17 g sample of an alkane hydrocarbon gas occupies a volume of 674 mL at 28°C and 741 mmHg.Alkanes are known to have the general formula CnH2n+2.What is the molecular formula of the gas in this sample? (R = 0.08206 L.atm/K.mol)

A gaseous compound is 30.4% nitrogen and 69.6% oxygen by mass. A 5.25-g sample of the gas occupies a volume of 1.00 L and exerts a pressure of 1.26 atm at -4.0°C. Which of these choices is its molecular formula?

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Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

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Calculate the volume occupied by 35.2 g of methane gas (CH₄)at 25°C and 1.0 atm.R = 0.08206 L.atm/K.mol.

A sample of N₂ gas occupies 2.40 L at 20°C. If the gas is in a container that can contract or expand at constant pressure, at what temperature will the N₂ occupy 4.80 L?

Air contains 78% N₂, 21% O₂, and 1% Ar, by volume. What is the density of air at 1,000.torr and -10°C?

What volume of CO₂ gas at 645 torr and 800 K could be produced by the reaction of 45 g of CaCO₃ according to the equation? CaCO₃(s) $\rarr$ CaO(s)+ CO₂(g)

Calculate the volume of H₂(g)at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

A pressure that will support a column of Hg to a height of 256 mm would support a column of water to what height? The density of mercury is 13.6 g/cm³; the density of water is 1.00 g/cm³.

A 2.50-L flask contains a mixture of methane (CH₄)and propane (C₃H₈)at a pressure of 1.45 atm and 20°C. When this gas mixture is then burned in excess oxygen, 8.60 g of carbon dioxide is formed. (The other product is water.)What is the mole fraction of methane in the original gas mixture?