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Physics · Class 11

Explore an ideal-gas state

Thermodynamics

Pressure, volume, temperature and gas amount are related by the equation of state. At fixed amount and temperature, doubling volume halves pressure. Internal energy of this ideal monatomic gas depends on temperature alone.

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Explore an ideal-gas state

நல்லியல்பு வாயுவில் pV = nRT. ஒரே வெப்பநிலையில் அளவு அதிகரித்தால் அழுத்தம் குறையும்.

Key notes, relationships and model limits

Key relationship

pV=nRT; U=3nRT/2 for an ideal monatomic gas.

Remember

Pressure, volume, temperature and gas amount are related by the equation of state. At fixed amount and temperature, doubling volume halves pressure. Internal energy of this ideal monatomic gas depends on temperature alone.

Common trap

An equation of state does not specify how heat or work was exchanged.

Model limits

Ideal monatomic gas in equilibrium. Each control selects a state, not a unique thermodynamic path. No nonideal or phase-transition corrections.

What you will learn

Connect state variables and distinguish state selection from process description.

Try the experiment

Try both scenarios, change one control, and predict the result before checking the graph and readouts.

Think of it this way

Change one input while keeping the others fixed, as you would in a controlled experiment.

Worked example

The worked gas has p≈2.494×10⁵ Pa and U=3×8.31446×300/2≈3741.5 J. At twice the volume, p halves and U stays the same.

Why this matters

The model connects explore an ideal-gas state with an observable reading. Check the equation and assumptions before applying it.

Before you start

SI units · algebra · graph reading

Check your understanding

What pressure does 1 mol at 300 K have in 0.01 m³?

Read the explanation

p=nRT/V=1×8.31446×300/0.01.

Course connection: Class XI Chapter 11. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.