A gas is contained in a thick walled balloon. When the pressure change from __ torr to 777 torr, the volume changes from 2.58 L to 1.53 L and the temperature changes from 368 K to 495 K

Answer is 342.6 torr.

Explanation:

Let's assume that the gas in the balloon is an ideal gas.

Then we can use combined gas law,

PV/T = k (constant)

Where, P is the pressure of the gas, V is volume of the gas and T is the temperature of the gas in Kelvin.

For two situations, we can use that as,

P₁V₁/T₁ = P₂V₂/T₂

P₁ = ?

V₁ = 2.58 L

T₁ = 368 K

P₂ = 777 torr

V₂ = 1.53 L

T₂ = 495 K

From substitution,

P₁ x 2.58 L / 368 K = 777 torr x 1.53 L / 495 K

P₁ = 342.6 torr

Hence, the answer is 342.6 torr.