For many purposes we can treat ammonia (NH,) as an ideal gas at temperatures above its boiling point of - 33. °C. Suppose the temperature of a sample of ammonia gas is lowered from 74.0 °C to 57.0 °C, and at the same time the pressure is decreased by 15.0%. O increase ol Does the volume of the sample increase, decrease, or stay the same? O decrease O stays the same If you said the volume increases or decreases, calculate the percentage change in the volume. Round your answer to the nearest percent.

or many purposes we on treat propane (C₂¹) as an ideal gas at temperatures above its boiling point of -42. °C. Suppose the temperature of a sample of propane gas is lowered from 12.0 °C to -31.0 °C, and at the same time the pressure is increased by 5.0%. Does the volume of the sample increase, decrease, or stay the same? O increase O decrease O stays the same If you said the volume increases or decreases, calculate the percentage change in % the volume. Round your answer to the nearest percent. 0 x10 X

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7. A sample of nitrogen gas is collected over water at 20°C and a pressure of 1.00 atm. The volume of the collected gas is 250.0 L. What is the partial pressure of the nitrogen gas? (At 20°C, the vapor pressure of water is 17.5 torr) Dalton's Law: Protal = P, Solving this problem: Pnitrogen = Ptotal - Pwater + P. nitrogen water 8. A sample of hydrogen gas is collected Over water at 22°C. The pressure of the resultant mixture is 765torr. What is the pressure that is exerted by the dry hydrogen alone?