Question

In the formula ∆U = q + w, work done by the system during expansion is (negative/positive), and heat (gained/lost) by the system is positive.

1. negative, gained 

2. negative, lost 

3. positive, gained 

4. positive, lost

Answer 1

Correct option 1. negative, gained

Explanation:

The sign conventions for process functions (like work and heat) are such that a positive sign is attributed to the system if it gains energy (in the form of heat or work).