In this worksheet, we will practice using Graham's law to calculate the relative effusion rates of gases from the square roots of the molar masses.

**Q1: **

An unknown hydrocarbon gas effuses 1.66 times more rapidly than .

What is the molar mass of the unknown gas?

What is the likely identity of the gas?

- A
- B
- C
- D
- E

**Q2: **

Which of the following gases diffuses faster than oxygen?

- A
- B
- C
- D
- E

**Q3: **

A balloon filled with helium gas is found to take 6.00 hours to deflate to of its original volume. How long will it take for an identical balloon filled with the same volume of hydrogen gas (instead of helium) to decrease its volume by ?

- A 8.45 hours
- B 3.01 hours
- C 4.98 hours
- D 4.26 hours
- E 1.34 hours

**Q4: **

When two cotton plugs, one moistened with ammonia and the other with hydrochloric acid, are simultaneously inserted into opposite ends of a glass tube that is 87.0 cm long, a white ring of forms where gaseous and gaseous first come into contact. Ammonia and hydrochloric acid react together according to the equation

How far from the end with ammonia would you expect the ring to form?

- A 43.5 cm
- B 29.0 cm
- C 8.01 cm
- D 51.7 cm
- E 72.1 cm

**Q5: **

It takes 243 s for mol to effuse through a tiny hole. Under the same conditions, how long will it take mol to effuse?

**Q6: **

What is the ratio of the rate of effusion of hydrogen to the rate of effusion of oxygen?

- A
- B
- C
- D
- E

**Q7: **

An equal number of moles of fluorine and helium diffuse into a chamber with no change in pressure or temperature. Calculate to 2 significant figures the diffusion rate of fluorine as a percentage of the diffusion rate of helium?

**Q8: **

An equal number of moles of nitrogen and a second gas diffuse into a chamber with no change in pressure or temperature. What is the molar mass of the second gas to the nearest gram per mole if its diffusion rate is two-thirds less than that of nitrogen?

**Q9: **

An equal number of moles of argon and a second gas diffuse into a chamber with no change in pressure or temperature. What is the molar mass of the second gas to the nearest g/mol if its diffusion rate is greater than that of argon?

**Q10: **

An equal number of moles of neon-20 and a second gas diffuse into a chamber with no change in pressure or temperature. Which of the following is a possible molecular formula for the second gas if its diffusion rate is lower than that of neon-20?

- A
- B
- C
- D
- E

**Q11: **

An equal number of moles of oxygen and hydrogen gas diffuse into a chamber with no change in pressure or temperature. By approximately what factor does the diffusion rate of oxygen differ from that of hydrogen?

- A
- B
- C
- D
- E

**Q12: **

The molecules in gas have molecular mass and an average speed , while the molecules in gas have molecular mass and an average speed .

If the gases are at the same temperature, how may the ratio be expressed in terms of and ?

- A
- B
- C
- D
- E

If the temperature of gas is doubled and the temperature of gas remains constant, by what factor does the ratio increase?

- A
- B
- C2
- D
- E4