Answer to Question #280073 in General Chemistry for Dennis

Question

A gas expands from 264 mL to 971 mL at constant temperature. Calculate the work done (in joules) by the gas if it expands

a. against a vacuum

b. against a constant pressure of 4.00 atm.

Answer 1

W$=-P\Delta\>V$

Where W$=$ work done against pressure

P$=$ pressure

$\Delta\>V=$ change in volume.

Part A

$P=0$

$\implies\>W=-0×\Delta\>V$

$=0\>J$

Part B

P$=4atm$

$1atm=101300N/m^2$

$\Delta\>V=971-264$

$=707ml$

$=707×10^{-6}m^3$

$W=707×10^{-6}×4×101300$

$=-286.5J$