Chemistry-First Law

NEET Chemistry First Law MCQ Question

Type: MCQ-numerical-Medium-Class 11

A system undergoes a change of state where it absorbs 50 J of heat and performs 30 J of work on the surroundings. What is the change in internal energy (ΔU) of the system?

A

20 J

B

80 J

C

-20 J

D

50 J

Correct Answer

Option A

Detailed Explanation

According to the first law of thermodynamics, ΔU = q + w. Here, q = 50 J and w = -30 J (since work is done by the system), so ΔU = 50 + (-30) = 20 J.

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