Gas laws — KCSE Chemistry
KCSE Chemistry · 78 practice questions · 4 syllabus objectives
What You'll Learn
Key learning outcomes for this topic, aligned to the KNEC KCSE syllabus.
State and apply Boyle's law (P₁V₁ = P₂V₂) to solve problems at constant temperature
State and apply Charles's law (V₁/T₁ = V₂/T₂) to solve problems at constant pressure
Apply the combined gas law and ideal gas equation (PV = nRT) to calculate pressure, volume, temperature or moles
Gas laws
Sample Questions
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A balloon filled with helium gas has a volume of 3 litres at a pressure of 1.5 atm and a temperature of 20°C. If the pressure is decreased to 1 atm while the temperature remains constant, what will be the new volume of the gas in litres? (3 marks)
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A gas sample at 25°C occupies a volume of 5 dm³ and exerts a pressure of 1.2 atm. If the gas is heated to 75°C while maintaining the pressure constant, what will be the new volume of the gas? (4 marks)
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Calculate the pressure exerted by 2 moles of carbon dioxide gas occupying a volume of 10 dm³ at a temperature of 300 K using the ideal gas equation. (3 marks)
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A balloon filled with gas has a volume of 2.0 litres at a temperature of 20°C. If the temperature is decreased to 0°C at constant pressure, what will be the new volume of the gas? (4 marks)
Why Practise Gas laws?
KNEC Aligned
Questions match the KCSE syllabus objectives and exam format exactly.
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