Question 1

A diver descends to a depth where the pressure is 3 atm. If the diver's lungs initially contain 6.0 L of air at the surface (1 atm), what will be the volume of air in the diver's lungs at this depth, assuming temperature remains constant and the diver does not exhale?

Accepted Answer

$$2.0\ \mathrm{L}$$

Question 2

Which of the following best explains why a helium balloon rises in air?

Accepted Answer

Helium has a lower density than air at the same temperature and pressure.

Question 3

A sample of gas occupies $$4.00\ \mathrm{L} at$$ $$300\ \mathrm{K}. $$What will its volume be at $$600\ \mathrm{K}$$, assuming constant pressure and amount?

Accepted Answer

$$8.00\ \mathrm{L}$$

Question 4

Which of the following actions will increase the volume of a gas sample, assuming constant temperature and number of moles?

Accepted Answer

Decreasing the pressure.

Question 5

A $$2.00\ \mathrm{mol}$$ sample of an ideal gas is at $$1.00\ \mathrm{atm}$$ and $$273\ \mathrm{K}. $$What is its volume?

Accepted Answer

$$44.8\ \mathrm{L}$$

Question 6

Which gas sample has the greatest density at STP?

Accepted Answer

A sample of $$\mathrm{CO_2$}$$

Question 7

A mixture contains $$2.0\ \mathrm{mol} of$$ $$\mathrm{O_2$}$$ and $$3.0\ \mathrm{mol} of$$ $$\mathrm{N_2$} in a$$ $$10.0\ \mathrm{L}$$ container at $$300\ \mathrm{K}. $$What is the total pressure of the mixture? $$(R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$})$$

Accepted Answer

Question 8

A gas mixture contains equal moles of $$\mathrm{He}$$ and $$\mathrm{Ne} at a $$total pressure of $$3.0\ \mathrm{atm}. $$What is the partial pressure of $$\mathrm{He}$$?

Accepted Answer

$$1.5\ \mathrm{atm}$$

Question 9

A $$5.00\ \mathrm{g}$$ sample of an unknown gas occupies $$2.00\ \mathrm{L} at$$ $$1.00\ \mathrm{atm}$$ and $$273\ \mathrm{K}. $$What is the molar mass of the gas?

Accepted Answer

$$56.0\ \mathrm{g\cdot $$mol^{-1}$$}$$

Question 10

Which of the following statements is consistent with the kinetic molecular theory of gases?

Accepted Answer

Gas particles are in constant, random motion and collisions are perfectly elastic.

Question 11

At the same temperature, which gas will have the highest average velocity?

Accepted Answer

$$\mathrm{H_2$}$$

Question 12

According to Graham’s law, what is the ratio of the rate of effusion of $$\mathrm{H_2$} to$$ $$\mathrm{O_2$}$$?

Accepted Answer

$$\sqrt{\dfrac{32}{2}}$$

Question 13

A gas is collected over water at $$25^\circ\mathrm{C}$$ and the total pressure is $$755\ \mathrm{mmHg}. If $$the vapor pressure of water at this temperature is $$24\ \mathrm{mmHg}$$, what is the partial pressure of the dry gas?

Accepted Answer

$$731\ \mathrm{mmHg}$$

Question 14

Which of the following best describes the behavior of real gases compared to ideal gases at high pressures?

Accepted Answer

Real gases have larger molar volumes than predicted by the ideal gas law.

Question 15

Which modification to the ideal gas law accounts for the finite volume of gas particles?

Accepted Answer

The van der Waals constant $$b is $$added to the volume term.

Question 16

If the temperature of a gas is doubled at constant pressure, what happens to the average kinetic energy of the gas particles?

Accepted Answer

It doubles.

Question 17

A rigid container holds a mixture of $$2.0\ \mathrm{mol}$$ $$\mathrm{N_2$}$$ and $$3.0\ \mathrm{mol}$$ $$\mathrm{O_2$}. If $$the total pressure is $$5.0\ \mathrm{atm}$$, what is the partial pressure of $$\mathrm{O_2$}$$?

Accepted Answer

$$3.0\ \mathrm{atm}$$

Question 18

Which of the following best explains why the pressure of a gas decreases when its volume increases at constant temperature?

Accepted Answer

Gas molecules collide with the container walls less frequently.

Question 19

A sample of $$\mathrm{Ne}$$ and $$\mathrm{Kr}$$ are at the same temperature. How does the root mean square velocity of $$\mathrm{Ne}$$ compare to that of $$\mathrm{Kr}$$?

Accepted Answer

The root mean square velocity of $$\mathrm{Ne} is $$approximately two times that of $$\mathrm{Kr}.$$

Chapter 6: Gases – General Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard