A sample of oxygen gas expands in volume from 1.6 L to 5.4 L at constant temperature. What is the work done in joules if the gas expands against a constant pressure of 0.80 atm?

Question

12897 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-12-24T19:20:09

The work is $- 307.95 " Joules".$

Work involved in a isotermic expansion is given by:

$W = - p cdot Delta V$

Then, if a $V_1$ volume of gas expands to $V_2$ under a pressure $p$ , the work done is:

$W = - p cdot (V_2 - V_1)$ .

We have:

$V_1 = 1.6 color(white) {"."} L = 1.6 cdot 10^{- 3} color(white) {"."} m^3$

$V_2 = 5.4 color(white) {"."} L = 5.4 cdot 10^{-3} color(white) {"."} m^3$

$p = 0.80 color(white) {"."} atm = 0.80 cdot 101,300 color(white) {"."} Pa = 81,040 color(white) {"."} Pa$

Then:

$W = - p cdot Delta V = - p cdot (V_2 - V_1) =$

$= - 81,040 color(white) {"."} Pa cdot (0.0054 - 0.0016) color(white) {"."} m^3 = - 307.95 color(white) {"."} J$ .