Everything Science Grade 11

CHAPTER 5. THERMAL PROPERTIES AND IDEAL GASES 5.4

V 2 =

6 �× 273 K

298 K

= 5. 5 �

5.4 The relationship between temperature andpressure

ESBBB

The pressure of a gas isdirectly proportional toits temperature, if the volume is kept constant(Fig-

ure 5.5). When the temperature of a gas increases, so does the energyof the particles. This causes

them to move more rapidly and to collide witheach other and with theside of the container more

often. Since pressure is ameasure of these collisions, the pressure of the gas increases with an increase

in temperature. The pressure of the gas will decrease if its temperature decreases.

Pressure

(^0) Temperature (K)
Figure 5.5: The relationship between the temperature and pressure of agas
In the same way that wehave done for the othergas laws, we can describe the relationship between
temperature and pressure using symbols, as follows:
T∝ p, therefore p = kT
We can also say that:
p
T
= k
and that, provided the amount of gas stays the same:
p 1
T 1

=

p 2

T 2

Exercise 5 - 3

1. A gas of unknown volume has a temperature of 14◦C. When the temperature of the gas is
   increased to 100◦C, the volume is found to be 5.5 �. What was the initial volume of the gas?