Question

1. A sample of a gas has a pressure of 854 torr at 288 °C. To what Celsius temperature must the gas be heated to double its pressure if there is no change in the volume of the gas?

2.Before taking a trip, you check the air in a tire of your automobile and find it has a pressure of 42 lb in-2 on a day when the air temperature is 16°C (about 61oF). After traveling some distance, you find that the temperature of the air in the tire has risen to 43°C (approximately 109°F). What is the air pressure in the tire at this higher temperature, expressed in lb in-2?

3. When 238 mL of oxygen at 773 torr and 19.0°C was warmed to 31.2°C, the pressure became 792 torr. What was the final volume (in mL)?

Answer 1

1. A sample of a gas has a pressure of 854 torr at 288 °C. To what Celsius temperature must the gas be heated to double its pressure if there is no change in the volume of the gas?

Solution :- P1= 854 torr

T1 = 288.0 C +273 = 561 K

P2 = 2*854 torr = 1708 torr

T2 = ?

P1/T1 = P2/T2

T2= P2*T1 / P1

     =1708 torr * 561 K / 854 torr

     = 1122 K

1122 K -273 = 849 C

So the final temperature is 849 ^oC

2.Before taking a trip, you check the air in a tire of your automobile and find it has a pressure of 42 lb in-2 on a day when the air temperature is 16°C (about 61oF). After traveling some distance, you find that the temperature of the air in the tire has risen to 43°C (approximately 109°F). What is the air pressure in the tire at this higher temperature, expressed in lb in-2?

Solution :- P1 = 42 lb in-2

T1 = 16 C +273 = 289 K

P2 = ?

T2 = 43 C +273 =316 K

P1/T1 = P2/T2

P2 = P1*T2/T1

    = 42 lb in-2 * 316 K / 289 K

    = 45.92 lb in-2

So the pressure is 45.92 lb in-2

3. When 238 mL of oxygen at 773 torr and 19.0°C was warmed to 31.2°C, the pressure became 792 torr. What was the final volume (in mL)?

Solution :-

V1 = 238 ml

T1 = 19.0 C +273 = 292 K

P1 = 773 torr

T2 = 31.2 C +273 = 304.2 K

P2 = 792 torr

V2 = ?

Formula

P1V1/T1 = P2V2/T2

V2 = P1V1*T2 / T1P2

     = 773 torr * 238 ml * 304.2 K / 292 K *792 torr

    = 242 ml

So the final volume is 242 ml