FRQ — Chemical Thermodynamics

Long answer·Standard multi-step (3/5)·Calculator allowed

Difficulty guide

The label describes the problem, not your ability.

1/5 - Foundational

Warm-up setup; checks one basic idea.

2/5 - Routine exam skill

Normal syllabus skill; usually one main rule or interpretation.

3/5 - Standard multi-step

Exam-style problem with multiple steps or a common trap.

4/5 - Hard exam skill

High-end exam problem; combines methods carefully.

5/5 - Challenge

Stretch problem beyond normal exam pressure.

Question

A gas expands from

1.0\text{ L}

4.0\text{ L}

against a constant external pressure of

2.0\text{ atm}

. During the process it absorbs

950\text{ J}

of heat. Use

1\text{ L atm}=101.3\text{ J}

Total: 5 marks

(a) Calculate the work in joule. (2 marks)

(b) Calculate $\Delta U$ . (2 marks)

Your response (optional — you can also work on paper)

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