The volume of a fixed mass of an ideal gas is doubled while the temperature is increased from 100 K to 400 K.

What is the final pressure in terms of its initial pressure?

a. 2 Pi

b. 3 Pi

c. 4 Pi

d. 1/2 Pi

c. 4 Pi

Explanation:

The pressure law states that the pressure of a gas is directly proportional to its temperature provided volume and other physical quantities remain constant.

If t is the temperature and p is the pressure of a gas,

p ∝ t

p = kt where k s the constant of proportionality

k = p/t

If t1 and p1 are the initial temperature and pressure respectively and

t2, p2 are the final temperature and pressure

p1/t1 = p2/t2

t1 = 100k, t2 = 400k

p2 = p1 * 400/100

p2 = 4t1

The final pressure of the gas is 4 times the initial pressure.