Question 1

Which of the following is the correct form of the Ideal Gas Law?

Accepted Answer

$$PV = nRT$$

Question 2

At STP, what volume does 1.00 mol of an ideal gas occupy?

Accepted Answer

$$22.4\ \mathrm{L}$$

Question 3

Which units must be used for the gas constant $$R in $$the equation $$PV = nRT$$ when pressure is in atm and volume is in liters?

Accepted Answer

$$0.0821\ \mathrm{L\ atm\ $$mol^{-1}$$\ K$$^{-1}$$}$$

Question 4

A gas has a density of $$1.77\ \mathrm{g/L} at$$ $$1.00\ \mathrm{atm}$$ and $$273\ \mathrm{K}. $$What is its molar mass?

Accepted Answer

$$39.9\ \mathrm{g/mol}$$

Question 5

Which equation allows you to calculate the density of a gas using the Ideal Gas Law?

Accepted Answer

$$d = \frac{PM}{RT}$$

Question 6

A sample of gas has a mass of $$4.50\ \mathrm{g}$$ and occupies $$2.00\ \mathrm{L} at$$ $$1.00\ \mathrm{atm}$$ and $$273\ \mathrm{K}. $$What is its molar mass?

Accepted Answer

$$50.0\ \mathrm{g/mol}$$

Question 7

If the pressure of a gas is doubled while temperature and amount remain constant, what happens to the volume?

Accepted Answer

It is halved.

Question 8

Which of the following best explains why the units of $$R$$ must match the other units in the Ideal Gas Law?

Accepted Answer

To ensure dimensional consistency and correct calculation of physical quantities.

Question 9

A medical oxygen tank contains $$10.0\ \mathrm{L} of$$ $$O_2 at$$ $$25.0\ \mathrm{C}$$ and $$2.00\ \mathrm{atm}. $$How many moles of $$O_2$$ are present?

Accepted Answer

$$0.82\ \mathrm{mol}$$

Question 10

A gas sample at STP has a mass of $$44.0\ \mathrm{g}$$ and occupies $$22.4\ \mathrm{L}. $$What is the identity of the gas?

Accepted Answer

Carbon dioxide ($$CO_2)$$

Question 11

Which of the following scenarios would require you to use the Ideal Gas Law to solve for molar mass?

Accepted Answer

You have the mass, pressure, volume, and temperature of a gas sample.

Question 12

A balloon contains $$2.00\ \mathrm{mol} of $$helium at $$1.00\ \mathrm{atm}$$ and $$273\ \mathrm{K}. $$What is the volume of the balloon?

Accepted Answer

$$44.8\ \mathrm{L}$$

Question 13

Which of the following is a correct rearrangement of the Ideal Gas Law to solve for molar mass ($$M) $$given mass ($$m$$), pressure ($$P$$), volume ($$V$$), and temperature ($$T$$)?

Accepted Answer

$$M = \frac{mRT}{PV}$$

Question 14

A gas cylinder contains $$5.00\ \mathrm{g} of an $$unknown gas at $$2.00\ \mathrm{atm}$$, $$3.00\ \mathrm{L}$$, and $$300\ \mathrm{K}. $$What is the molar mass of the gas?

Accepted Answer

$$20.5\ \mathrm{g/mol}$$

Question 15

Which of the following statements about the molar volume of a gas at STP is correct?

Accepted Answer

1 mole of any ideal gas occupies $$22.4\ \mathrm{L} at $$STP.

Question 16

A chemical reaction produces $$2.00\ \mathrm{mol} of$$ $$CO_2$$ gas at $$1.00\ \mathrm{atm}$$ and $$273\ \mathrm{K}. $$What volume of $$CO_2 is $$produced?

Accepted Answer

$$44.8\ \mathrm{L}$$

Question 17

A gas sample has a density of $$2.50\ \mathrm{g/L} at$$ $$1.00\ \mathrm{atm}$$ and $$273\ \mathrm{K}. $$What is the molar mass of the gas?

Accepted Answer

$$56.0\ \mathrm{g/mol}$$

Question 18

Which of the following is NOT a correct application of the Ideal Gas Law?

Accepted Answer

Using $$PV = nRT to $$calculate the mass of a solid.

Question 19

A sample of $$H_2$$ gas at STP occupies $$1.24\ \mathrm{L}. $$How many grams of water can be formed when it completely reacts with oxygen?

Accepted Answer

$$0.997\ \mathrm{g}$$

Ideal Gas Law: Applications, Density, and Molar Mass Determinations

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