Question

A gas expands againts a constant external pressure of `2.00` atm, increasing its volume by `3.40L` . Simultaneously, the system absorbs `400J` of heat from its surroungs. What is `DeltaE` , in joules, for this gas?
A. `-689`
B. `-289`
C. `+400`
D. `+289`

Answer 1

Correct Answer - C
Given, `P=2.00` atm,
`DeltaV=3.4L`
`q=400J`
Work done by das `w=-PDeltaV`
`=-2xx3.4`
`=-6.8L` atm
`=-6.8xx101.32J`
`=-688.976J`
`DeltaE=q+(-w)`
`=400+(-688.976)`
`=-288.976~~-289J`