Question

If pressure of gas contained in a closed vessel is increased by 0.4% when heated by 1°C, its initial temperature must be ______.

विकल्प

• 200°C

• 250°C

• 300°C

• 350°C

Answer 1

If pressure of gas contained in a closed vessel is increased by 0.4% when heated by 1°C, its initial temperature must be 250°C.

Explanation:

Since the gas is in a closed vessel, its volume is constant. According to Gay-Lussac’s Law, pressure is directly proportional to absolute temperature (P ∝ T).

A 0.4% increase in pressure means the final pressure is 1.004 times the original. A 1°C rise is the same as a 1 K rise.

`P/T = (1.004 P)/(T + 1)`

T + 1 = 1.004 T

1 = 0.004 T

T = `1/0.004`

= 250°C