Question

A gas at 250 K has a pressure of 0.00008 Pa. If the pressure drops to 0.00002 Pa, what is the new temperature?

500 K

1000 K

125 K

62.5 K

Answer 1

Answer: -

If a gas at 250 K has a pressure of 0.00008 Pa and the pressure drops to 0.00002 Pa, 62.5 K is the new temperature

Explanation: -

Initial Pressure P₁ = 0.00008 Pa

Final Pressure P₂ = 0.00002 Pa

Initial Temperature T₁ = 250 K

Since the volume is not mentioned, it remains constant.

So initial Volume V₁ = Final volume V₂

Now using the combined gas equation

`(P1 V1)/(T1)` =
`(P2 V2)/(T2)`

Final Temperature T₂ =
`(P 2 V2 T1)/(P1 V1)`

Plugging in the values,

T₂ =
`(0.00002 Pa x V2 x 250 K)/(0.00008 Pa x V1)`

As V₂ = V₁, they cancel each other.

T₂ = 62.5 K