Question 1

A balloon is placed in a bell jar and the pressure is reduced from 782 torr to 0.250 atm. If the final volume of the balloon is $$2.78 	imes 10^3$ mL, what was its initial volume? (Assume temperature is constant.)

Accepted Answer

$$914$$\ mL

Question 2

A steel tank is filled with helium to a volume of $$1.61 L at$$ $$734$$ torr. What will be the volume of the gas after it has been released and its pressure has dropped to $$715$$ torr, assuming the temperature remains constant?

Accepted Answer

$$1.65$$\ L

Question 3

Methane is placed in a $$10.0-L $$container at $$25\ ^\circC $$and $$725$$ torr. The gas is then moved to a $$7.50-L $$container at $$25\ ^\circC. $$What is the gas pressure in the second container?

Accepted Answer

$$967$$\ torr

Question 4

A reaction occurring in a cylinder equipped with a moveable piston produces $$0.621 L of $$gas. If there were $$0.120$$ mol of gas before the reaction and the initial volume was $$2.50 L$$, what is the final number of moles of gas? (Assume constant pressure and temperature.)

Accepted Answer

$$0.150$$\ mol

Question 5

A $$3.0 L $$sample of $$N_2 is at$$ $$25\ ^\circC. $$What volume will the gas occupy at $$75\ ^\circC$$, assuming constant pressure?

Accepted Answer

$$3.51$$\ L

Question 6

A basketball contains $$0.21$$ mol of gas at a total pressure of $$24.3$$ psi and $$25\ ^\circC. $$What is the volume of the basketball? ($$1\ atm = 14.7\ psi)$$

Accepted Answer

$$0.20$$\ L

Question 7

A gas occupies $$10.0 L at$$ $$44.1$$ psi and $$27\ ^\circC. $$What volume will it occupy at STP?

Accepted Answer

$$29.2$$\ L

Question 8

A gas is confined in a $$5.0-L $$container at $$328$$ torr and $$27\ ^\circC. If $$the gas has a molar mass of $$32.0 g/$$mol, how many grams of gas are in the sample?

Accepted Answer

$$0.35$$\ g

Question 9

A gas occupies $$3.65 L at$$ $$298 K $$and $$745$$ torr. Find its volume at $$273 K $$and $$745$$ torr.

Accepted Answer

$$3.35$$\ L

Question 10

How many moles of neon occupy a volume of $$14.3 L at $$STP?

Accepted Answer

$$0.638$$\ mol

Question 11

At STP, what is the volume occupied by $$11 g of$$ $$SO_2$$?

Accepted Answer

$$3.85$$\ L

Question 12

What is the molar mass of a gas at $$388$$ torr and $$45\ ^\circC if$$ $$206 ng of $$the gas occupies $$0.500 mL$$?

Accepted Answer

$$44.0$$\ g/mol

Question 13

A $$63.8-mL $$glass bulb is filled with a gas at $$22\ ^\circC $$and $$1.00$$ atm. The bulb gains $$0.103 g in $$mass. Is the gas $$N_2$$, $$Ne$$, or $$Ar$$?

Accepted Answer

$$Ar$$

Question 14

Airbags are inflated by nitrogen gas generated by the rapid decomposition of sodium azide: $$2NaN_3(s) \rightarrow 2Na(s) + 3N_2(g). If an $$airbag has a volume of $$36 L $$and is to be filled with nitrogen gas at $$1.15$$ atm and $$26\ ^\circC$$, how many grams of $$NaN_3$$ must be decomposed?

Accepted Answer

$$70.2$$\ g

Question 15

Silver oxide decomposes when heated: $$2Ag_2O(s) \rightarrow 4Ag(s) + O_2$(g). If$$ $$0.65 L of$$ $$O_2$$ gas is collected at $$27\ ^\circC $$and $$1.00$$ atm, what mass of $$Ag_2O$$ was decomposed?

Accepted Answer

$$3.62$$\ g

Question 16

During fermentation, yeast converts glucose ($$C_6H_{12}O_6$) to ethanol and carbon dioxide: C_6H$$_{12}$$O_6(s$$) \rightarrow 2C_2H_5OH(l) + 2CO_2(g)$$. If 1.44$ L of CO_2$ gas is collected at 298$ K and 0.984$ atm, what mass of glucose was consumed?

Accepted Answer

$$2.80$$\ g

Question 17

A mixture of two gases, methane and oxygen, are in a $$10.5 L $$container at $$25\ ^\circC. $$Methane has a partial pressure of $$0.175$$ atm and oxygen has a partial pressure of $$0.250$$ atm. What is the total pressure of the system?

Accepted Answer

$$0.425$$\ atm

Question 18

A $$5.0 L $$sample of $$CO_2 is at$$ $$1$$ atm and $$300 K. In a $$separate $$15.0 L $$container, $$O_2 is at$$ $$2$$ atm and $$400 K. $$The two gases are combined into an empty $$10.0 L $$container. Calculate the total pressure in the container and the partial pressure of each gas in the new container.

Accepted Answer

Total pressure: $$2.08$$\ atm; $$CO_2$$: $$0.50$$\ atm; $$O_2$$: $$1.58$$\ atm

Gas Laws and Applications in General Chemistry

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