Assume that the volume of a balloon filled with H2 is 1.00 L at 25.0°C.

Question

Calculate the volume of the balloon when it is cooled to -78.0°C in a low-temperature bath made by adding dry ice to acetone.

Answer 1

From the ideal gas law, V₂ /V₁ = T₂ /T₁ for the same pressure and quantity of gas. V₂ = (1.00 L) (-78 +273 K) / (25 +273K) = 0.654 L.