Question

A sample of a gas (1.50 mol) is contained in a 15.0 l cylinder. the temperature is increased from 100 °c to 150 °c. what is the ratio of final pressure to initial pressure?

Answer 1

Given:

Moles of gas, n = 1.50 moles

Volume of cylinder, V = 15.0 L

Initial temperature, T1 = 100 C = (100 + 273)K = 373 K

Final temperature, T2 = 150 C = (150+273)K = 423 K

To determine:

The pressure ratio

Explanation:

Based on ideal gas law:

PV = nRT

P= pressure; V = volume; n = moles; R = gas constant and T = temperature

under constant n and V we have:

P/T = constant

(or) P1/P2 = T1/T2 ---------------Gay Lussac's law

where P1 and P2 are the initial and final pressures respectively

substituting for T1 and T2 we get:

P1/P2 = 373/423 = 0.882

Thus, the ratio of P2/P1 = 1.13

Ans: The pressure ratio is 1.13