Question

A sample of gas absorbs 4000 kJ of heat and surrounding does 2000 J of work on sample. What is the value of ∆U?

Options

• 4002 kJ

• 6000 kJ

• 4000 kJ

• 2000 kJ

Answer 1

4002 kJ

Explanation:

Given, q = + 4000 kJ ........(heat absorbed)

W = + 2000 J .........(work done by surrounding)

= 2 kJ or `(2000/1000)` kJ

Using the first law of thermodynamics,

ΔU = q + W

= (4000 + 2) kJ

= 4002 kJ