Question 1

An unknown gas contains 83% C and 17% H by mass.If effuses at 0.87 times the rate of CO2 gas under the same conditions.What is the molecular formula of the unknown gas?

Accepted Answer

A) C2H5 
B) C3H3 
C) C4H10 
D) C7H17

Question 2

The molecule believed to be most responsible for global warming is ________.

Accepted Answer

The answer of The molecule believed to be most responsible...

Question 3

How many liters of SO3(g)are produced at 25°C and 1.00 atm from the combustion of 1.00 kg of coal which is 1.00% S by weight? Assume all the sulfur in the coal ends up as SO3.

Accepted Answer

A) 0.640 L 
B) 5.08 L 
C) 7.63 L 
D) 11.4 L

Question 4

Which statement about real gases is true?

Accepted Answer

A) The volume of the gas particles is zero. 
B) The mass of the gas particles is zero. 
C) Forces of attraction and repulsion exist between gas particles at close range. 
D) The behavior of real gases can be exactly predicted using the ideal gas law.

Question 5

A glass tube has one end in a dish of mercury and the other end closed by a stopcock.The distance from the surface of the mercury to the bottom of the stopcock is 800 mm,as indicated by the meter stick shown in the drawing below.The apparatus is at 20°C,and the mercury level in the tube is the same as that in the dish. 
-Which drawing best shows the approximate level of the mercury in the tube when the temperature of the entire apparatus is lowered from +20°C to -20°C?

Accepted Answer

A) drawing (1) 
B) drawing (2) 
C) drawing (3) 
D) drawing (4)

Question 6

What is the Celsius temperature of 100.0 g of chlorine gas in a 45.0-L container at 800 mm Hg?

Accepted Answer

A) -68°C 
B) 136°C 
C) 205°C 
D) 410°C

Question 7

Effusion of a 1:1 mixture of two gases,represented by unshaded and shaded spheres in the diagram below,through a small pinhole produces the result shown below.The shaded spheres have a molecular mass of 32 amu.Which gas molecules have the higher average speed and what is the molecular mass of the unshaded molecules?

Accepted Answer

A) Unshaded molecules have higher average speed and molecular mass = 14 amu. 
B) Unshaded molecules have higher average speed and molecular mass = 21 amu. 
C) Unshaded molecules have lower average speed and molecular mass = 48 amu. 
D) Unshaded molecules have lower average speed and molecular mass = 72 amu.

Question 8

If the pressure in a gas container that is connected to an open-end U-tube manometer is 126 kPa and the pressure of the atmosphere at the open end of the tube is 732 mm Hg,the level of mercury in the tube will

Accepted Answer

A) be 213 mm higher in the arm open to the atmosphere. 
B) be 213 mm higher in the arm connected to the gas cylinder. 
C) be 945 mm higher in the arm open to the atmosphere. 
D) be 945 mm higher in the arm connected to the gas cylinder.

Question 9

Pressure is defined as

Accepted Answer

A) force divided by unit area. 
B) force times unit area. 
C) mass divided by acceleration. 
D) mass times acceleration.

Question 10

Gases do not behave ideally under conditions of ________ pressure and ________ temperature.

Accepted Answer

The answer of Gases do not behave ideally under conditions...

Question 11

Assume that you have a sample of gas in a cylinder with a moveable piston,as shown in diagram (1).The initial pressure,number of moles,and temperature of the gas are noted on the diagram. 
-Which diagram (2)-(4)most closely represents the result of doubling the pressure and doubling the temperature while keeping the number of moles of gas constant?

Accepted Answer

A) diagram (2) 
B) diagram (3) 
C) diagram (4)

Question 12

The pressure in the eye of a hurricane is less than atmospheric pressure.Which one of the following pressure readings could not have been taken in the eye of a hurricane?

Accepted Answer

A) 16 lbs/in2 
B) 66 cm Hg 
C) 660 mm Hg 
D) 9.45 × 104 Pa

Question 13

You are given two flasks of equal volume.One contains H2 at 0°C and 1 atm while the other contains CO2 at  and 2 atm.Which of the following quantities will be the same for both flasks?

Accepted Answer

A) average molecular kinetic energy 
B) average molecular speed 
C) density 
D) number of molecules present

Question 14

If the pressure in a gas container that is connected to an open-end U-tube manometer is 106 kPa and the pressure of the atmosphere at the open end of the tube is 700 mm Hg,the level of mercury in the tube will be

Accepted Answer

A) 95 mm higher in the arm open to the atmosphere. 
B) 95 mm higher in the arm connected to the gas cylinder. 
C) 795 mm higher in the arm open to the atmosphere. 
D) 795 mm higher in the arm connected to the gas cylinder.

Question 15

According to Graham's law,the rate of effusion of a gas is inversely proportional to the ________.

Accepted Answer

The answer of According to Graham's law,the rate of effusion...

Question 16

Some assumptions from the kinetic molecular theory are listed below.Which one is most frequently cited to explain diffusion of a gas?

Accepted Answer

A) The average kinetic energy of gas particles is proportional to the Kelvin temperature. 
B) Collisions of gas particles are elastic and total kinetic energy of the gas is constant. 
C) A gas consist of tiny particles moving in random straight line motion. 
D) The volume of the particles is negligible compared to the volume of the gas.

Question 17

In the laboratory,hydrogen gas is usually made by the following reaction: Zn(s)+ 2 HCl(aq)→ H2(g)+ ZnCl2(aq)
How many liters of H2 gas,collected over water at an atmospheric pressure of 752 mm Hg and a temperature of 21.0°C,can be made from 2.566 g of Zn and excess HCl? The partial pressure of water vapor is 18.65 mm Hg at 21.0°C.

Accepted Answer

A) 0.0701 L 
B) 0.939 L 
C) 0.959 L 
D) 0.981 L

Question 18

At 298 K which is larger rate of effusion or rate of diffusion?

Accepted Answer

The answer of At 298 K which is larger rate...

Question 19

When 12.0 g of zinc metal reacts with excess HCl,how many liters of H2 gas are produced at STP?

Accepted Answer

A) 0.243 L 
B) 0.486 L 
C) 4.11 L 
D) 8.23 L

Question 20

A container filled with gas is connected to an open-end U-tube manometer that is filled with mineral oil.The pressure in the gas container is 770 mm Hg and atmospheric pressure is 754 mm Hg.What will be the difference in the levels of mineral oil in the two arms of the manometer if the densities of Hg and mineral oil are 13.6 g/mL and 0.822 g/mL respectively?

Accepted Answer

A) 1.15 mm 
B) 15.6 mm 
C) 16.0 mm 
D) 264 mm

Exam 10: Gases: Their Properties and Behavior

An unknown gas contains 83% C and 17% H by mass.If effuses at 0.87 times the rate of CO₂ gas under the same conditions.What is the molecular formula of the unknown gas?

The molecule believed to be most responsible for global warming is ________.

How many liters of SO₃(g) are produced at 25°C and 1.00 atm from the combustion of 1.00 kg of coal which is 1.00% S by weight? Assume all the sulfur in the coal ends up as SO₃.

Which statement about real gases is true?

What is the Celsius temperature of 100.0 g of chlorine gas in a 45.0-L container at 800 mm Hg?

If the pressure in a gas container that is connected to an open-end U-tube manometer is 126 kPa and the pressure of the atmosphere at the open end of the tube is 732 mm Hg,the level of mercury in the tube will

Pressure is defined as

Gases do not behave ideally under conditions of pressure and temperature.

The pressure in the eye of a hurricane is less than atmospheric pressure.Which one of the following pressure readings could not have been taken in the eye of a hurricane?

You are given two flasks of equal volume.One contains H₂ at 0°C and 1 atm while the other contains CO₂ at and 2 atm.Which of the following quantities will be the same for both flasks?

If the pressure in a gas container that is connected to an open-end U-tube manometer is 106 kPa and the pressure of the atmosphere at the open end of the tube is 700 mm Hg,the level of mercury in the tube will be

According to Graham's law,the rate of effusion of a gas is inversely proportional to the ________.

Some assumptions from the kinetic molecular theory are listed below.Which one is most frequently cited to explain diffusion of a gas?

At 298 K which is larger rate of effusion or rate of diffusion?

When 12.0 g of zinc metal reacts with excess HCl,how many liters of H₂ gas are produced at STP?

Exam 10: Gases: Their Properties and Behavior

An unknown gas contains 83% C and 17% H by mass.If effuses at 0.87 times the rate of CO2 gas under the same conditions.What is the molecular formula of the unknown gas?

The molecule believed to be most responsible for global warming is ________.

How many liters of SO3(g) are produced at 25°C and 1.00 atm from the combustion of 1.00 kg of coal which is 1.00% S by weight? Assume all the sulfur in the coal ends up as SO3.

Which statement about real gases is true?

What is the Celsius temperature of 100.0 g of chlorine gas in a 45.0-L container at 800 mm Hg?

If the pressure in a gas container that is connected to an open-end U-tube manometer is 126 kPa and the pressure of the atmosphere at the open end of the tube is 732 mm Hg,the level of mercury in the tube will

Pressure is defined as

Gases do not behave ideally under conditions of ________ pressure and ________ temperature.

The pressure in the eye of a hurricane is less than atmospheric pressure.Which one of the following pressure readings could not have been taken in the eye of a hurricane?

You are given two flasks of equal volume.One contains H2 at 0°C and 1 atm while the other contains CO2 at and 2 atm.Which of the following quantities will be the same for both flasks?

If the pressure in a gas container that is connected to an open-end U-tube manometer is 106 kPa and the pressure of the atmosphere at the open end of the tube is 700 mm Hg,the level of mercury in the tube will be

According to Graham's law,the rate of effusion of a gas is inversely proportional to the ________.

Some assumptions from the kinetic molecular theory are listed below.Which one is most frequently cited to explain diffusion of a gas?

At 298 K which is larger rate of effusion or rate of diffusion?

When 12.0 g of zinc metal reacts with excess HCl,how many liters of H2 gas are produced at STP?

An unknown gas contains 83% C and 17% H by mass.If effuses at 0.87 times the rate of CO₂ gas under the same conditions.What is the molecular formula of the unknown gas?

How many liters of SO₃(g) are produced at 25°C and 1.00 atm from the combustion of 1.00 kg of coal which is 1.00% S by weight? Assume all the sulfur in the coal ends up as SO₃.

Gases do not behave ideally under conditions of pressure and temperature.

You are given two flasks of equal volume.One contains H₂ at 0°C and 1 atm while the other contains CO₂ at and 2 atm.Which of the following quantities will be the same for both flasks?

When 12.0 g of zinc metal reacts with excess HCl,how many liters of H₂ gas are produced at STP?