Answer to Question #70951 in General Chemistry for Cooper Wade

Question

A 9.8 g piece of dry ice (solid CO2) is placed in a balloon at room temperature (20oC) and sealed. Give a qualitative and quantitative account of what will be observed as the dry ice comes to room temperature. (Note: R = 8.31JK-1 mol-1)

Answer 1

a) The piece of dry ice changes from a solid to a gas, so the volume of a balloon will increase:
Amount of the dry ice: 9.8 g / 44 gmol-1 = 0.223 mol
Volume of the gaseous CO2: 0.223 mol ∙ 22.4 lmol-1 = 5 l
b) Work done by a system (ΔT = 98 K): 8.31 JK-1 mol-1 ∙ 98 K ∙ 0.223 mol = 181.6 J