Question

A reaction taking place in a container with a piston-cylinder assembly at constant temperature produces a gas, and the volume increases from 127 mL to 654 mL against an external pressure of 860 torr. Calculate the work done in Joules (J)

Answer 1

Answer:

60.4 J

Explanation:

The work done by the gas is given by:

$W=p(V_f-V_i)$

where

p is the gas pressure

$V_f$ is the final volume of the gas

$V_i$ is the initial volume

We must convert all the quantities into SI units:

$p=860 torr \cdot \frac{1.013\cdot 10^5 pa}{760 torr}=1.146\cdot 10^5 Pa$

$V_i = 127 mL = 0.127 L = 0.127 dm^3 = 0.127 \cdot 10^{-3}m^2$

$V_f = 654 mL = 0.654 L = 0.654 dm^3 = 0.654 \cdot 10^{-3}m^2$

So the work done is

$W=(1.146\cdot 10^5 Pa)(0.654\cdot 10^{-3} m^3-0.127\cdot 10^{-3} m^3)=60.4 J$