E - Pressure and Temperature - Paper 2

Question 1

A gas is heated from 27ºC to 127°C. The initial pressure was 150000 Pa. Calculate the final pressure.

Answer 1

First we must convert into Kelvin

27oC = 27 + 273 = 300 K

127oC = 127 + 273 = 400 K

P1 / T1 = P2 / T2

150000 / 300 = P2 / 400

(150000 x 400) / 300 = P2

60000000 / 300 = P2

200000 Pa = P2

Question 2

A gas is reduced in pressure from 1000000 Pa to 200000 Pa. If the final temperature is 0oC what was the initial temperature in celsius?

Answer 2

First we must convert into Kelvin

0oC = 0 + 273 = 273 K

P1 / T1 = P2 / T2

1000000 / T1 = 200000 / 273

1000000 x 273 = 200000 x T1

T1 = 1000000 x 273 / 200000

T1 = 273000000 / 200000

T1 = 1365 K

= 1365 - 273

= 1092oC

Question 3

A gas is heated from 57oC to 327oC. The initial pressure was 100000 Pa. Calculate the final pressure.

Answer 3

57oC = 57 + 273 = 330 K

327oC = 327 + 273 = 600 K

P1 / T1 = P2 / T2

100000 / 330 = P2 / 600

(100000 x 600) / 330 = P2

60000000 / 330 = P2

181818.18 Pa = P2

Question 4

A gas is reduced in pressure from 500000 Pa to 100000 Pa. If the final temperature is 27oC what was the initial temperature in celsius?

Answer 4

27oC = 27+ 273 = 300 K

P1 / T1 = P2 / T2

500000 / T1 = 100000 / 300

500000 x 300 = 100000 x T1

T1 = (500000 x 300) / 100000

T1 = 165000000 / 100000

T1 = 1500 K

= 1500 - 273

= 1227oC