Let’s solve a sample numerical problem (from the gas chapter) using Gay Lussac’s law or pressure law. The formula to be used is as follows: P1/T1 = P2/T2
A chamber of the constant volume contains hydrogen gas. When the chamber is immersed in a bath of melting ice (0°C), the pressure of the gas is 1.07 × 102kPa. What pressure will be indicated when the chamber is brought to 100°C ?
Solution: T1=273 + 0 = 273 K,
p1=1.07 × 102 kPa =107 kPa
T2=273 + 100 = 373 K,
p2 = ?
Since volume remains constant, therefore, according to Gay Lussac’s law: P1/T1 = P2/T2
=> P2 = (P1/T1)x T2 = 107 x 373 / 273 =1.462 x 102 kPa