Question 1

Which of the following best describes the role of $$\mathrm{H_2SO_4} in $$the reaction:

$$\mathrm{Ca($$HCO_3$$)_2(aq) + H_2SO_4(aq) \rightarrow $$CaSO_4$$(s) + 2H_2CO_3(aq)}$$?

Accepted Answer

It provides sulfate ions to precipitate calcium as $$\mathrm{$$CaSO_4$$}.$$

Question 2

A 5.00 L rigid container at 55.0 $$^\circC $$contains 0.40 g of $$\mathrm{N_2$}$$, 0.60 g of $$\mathrm{O_2$}$$, and 0.80 g of $$\mathrm{CO_2$}. $$What is the total pressure in the container? (Use $$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$})$$

Accepted Answer

$$0.78\ \mathrm{atm}$$

Question 3

Which of the following statements about the kinetic molecular theory of gases is FALSE?

Accepted Answer

Gas particles lose energy during elastic collisions.

Question 4

A mixture contains 2.0 moles of $$\mathrm{H_2$}$$ and 1.0 mole of $$\mathrm{N_2$} in a 2.0 L $$container at 298 K. What is the partial pressure of $$\mathrm{H_2$}$$? ($$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$})$$

Accepted Answer

$$24.6\ \mathrm{atm}$$

Question 5

Which gas will have the highest average molecular speed at 298 K?

Accepted Answer

$$\mathrm{H_2$}$$

Question 6

A sample of $$\mathrm{NO_2$}$$ effuses through a porous membrane in 38 seconds. Under the same conditions, an unknown gas effuses in 19 seconds. What is the molar mass of the unknown gas? ($$M_{NO_2$} = 46\ \mathrm{g/mol})$$

Accepted Answer

$$11.5\ \mathrm{g/mol}$$

Question 7

Which of the following changes will increase the pressure of a gas in a rigid container?

Accepted Answer

Increasing the amount of gas

Question 8

A 2.0 L flask contains a mixture of $$\mathrm{CO}$$ and $$\mathrm{CO_2$} at a $$total pressure of 1.0 atm. If the partial pressure of $$\mathrm{CO} is 0.6 $$atm, what is the mole fraction of $$\mathrm{CO_2$}$$?

Accepted Answer

$$0.4$$

Question 9

Which of the following best explains why real gases deviate from ideal behavior at high pressures?

Accepted Answer

The volume of gas particles becomes significant compared to the container volume.

Question 10

A laboratory procedure requires the precipitation of $$\mathrm{$$CaCO_3$$} by $$mixing $$\mathrm{$$CaCl_2$$}$$ and $$\mathrm{Na_2CO_3}$$ solutions. If 50.0 mL of 0.10 M $$\mathrm{$$CaCl_2$$} is $$mixed with 50.0 mL of 0.10 M $$\mathrm{Na_2CO_3}$$, what is the maximum mass of $$\mathrm{$$CaCO_3$$}$$ that can be formed? ($$M_{$$CaCO_3$$} = 100\ \mathrm{g/mol})$$

Accepted Answer

$$0.50\ \mathrm{g}$$

Question 11

Which of the following is the correct balanced equation for the reaction between $$\mathrm{Ca($$HCO_3$$)_2}$$ and $$\mathrm{H_2SO_4}$$?

Accepted Answer

$$\mathrm{Ca($$HCO_3$$)_2(aq) + H_2SO_4(aq) \rightarrow $$CaSO_4$$(s) + 2H_2CO_3(aq)}$$

Question 12

A gas sample occupies 5.00 L at 300 K and 1.00 atm. What will be its volume at 600 K and 2.00 atm?

Accepted Answer

$$5.00\ \mathrm{L}$$

Question 13

Which of the following statements is TRUE regarding the diffusion of gases?

Accepted Answer

Lighter gases diffuse faster than heavier gases.

Question 14

A mixture of $$\mathrm{H_2$}$$ and $$\mathrm{O_2$}$$ gases is ignited in a closed container. After the reaction, which gas will remain if $$\mathrm{H_2$} is in $$excess?

Accepted Answer

$$\mathrm{H_2$}$$

Question 15

Which of the following is NOT an assumption of the kinetic molecular theory?

Accepted Answer

Gas particles exert attractive forces on each other.

Question 16

A 2.0 L container holds 0.10 mol $$\mathrm{N_2$}$$ and 0.20 mol $$\mathrm{O_2$} at 298 K. $$What is the total pressure in the container? ($$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$})$$

Accepted Answer

$$3.66\ \mathrm{atm}$$

Question 17

Which of the following best describes the effect of increasing temperature on the average kinetic energy of a gas?

Accepted Answer

It increases linearly with temperature in Kelvin.

Question 18

A sample of $$\mathrm{CO_2$}$$ gas at 1.00 atm and 273 K is compressed to 2.00 atm at constant temperature. What happens to the volume?

Accepted Answer

It halves.

Question 19

Which of the following is the correct expression for the root mean square speed ($$u_{rms}) of a $$gas molecule?

Accepted Answer

$$u_{rms} = \sqrt{\frac{3RT}{M}}$$

General Chemistry: Gases, Chemical Reactions, and Stoichiometry Study Notes

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