Moles and particles
A 9.0 g sample of water has molar mass 18 g mol⁻¹. Calculate the amount and number of molecules.
← Topic 15CIE-STYLE QUESTIONS
Structured practice
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Ideal gas equation
A gas contains 0.15 mol at 320 K in 3.0 × 10⁻³ m³. Calculate its pressure.
Two equilibrium states
A fixed gas has p₁ = 90 kPa, V₁ = 2.4 dm³ and T₁ = 300 K. Find p₂ when V₂ = 1.8 dm³ and T₂ = 330 K.
Model assumptions
Explain why a real gas deviates most strongly from ideal behaviour when it is cold and highly compressed.
Origin of pressure
A molecule with normal velocity component cₓ strikes a wall elastically. State its momentum change and explain how many impacts create pressure.
Mean kinetic energy
Calculate the mean translational kinetic energy of a molecule at 450 K.
RMS speed comparison
Gas A has four times the molar mass of gas B. Both are at the same temperature. Compare their rms speeds.