## 4B.5

$\Delta U=q+w$

Amy Luu 2G
Posts: 105
Joined: Wed Sep 18, 2019 12:19 am

### 4B.5

An ideal gas in a cylinder was placed in a heater and gained 5.50 kJ of energy as heat. If the cylinder increased in volume from 345 mL to 1846 mL against an atmospheric pressure of 750. Torr during this process, what is the change in internal energy of the gas in the cylinder?

I know to solve this problem we need to find the amount of work done by the system. However, how do we know whether the system is reversible or irreversible to determine which formula to use w=-Pex$\Delta$V or w=-nRTln(V2/V1)?