The pressure in a car tire is 198 kpa at 27°c. after a long drive the pressure is 225 kpa. what is the temperature of the air in the tire? assume that the volume is constant.

340.9°k ~ 67.8°C

Explanation:

This is an example of Gay-Lussac's law, which states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature. This means that if the volume increases, so does the temperature, and vice versa.

The equation for this gas law is:

P1/T1 = P2/T2

Known

P1 = 198 kPa

T1 = 27°C + 273.15 = 300°K ← Temp. must be in Kelvins

P2 = 225 kPa

T2 = ?

Solution

Rearrange the equation to isolate T2

Input the known values and solve.

T2 = T1P2/P1

Where:

T2 = 300°K × 225kPa/198kPa = 340.91°K

T2 in °C = 340.91°K − 273.15 = 67.8°C

note: answers were rounded off to one decimal point.