Unit 1: Structure 1: Models of the Particulate Nature of Matter
Topic 1.5: Ideal Gases Questions
Practice 15 exam-style questions for IB Chemistry Topic 1.5. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.
1Calculate2 marks
Calculate the volume, measured at STP, of 0.350 mol of oxygen gas, O₂.
(Vₘ = 22.7 dm³ mol⁻¹.)
(Vₘ = 22.7 dm³ mol⁻¹.)
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Unlock Question2calculate3 marks
A gas occupies 300 cm³ at 20.0 °C. Calculate its volume at 100.0 °C, the pressure remaining constant.
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Explain, using the kinetic molecular theory, why the pressure of a fixed mass of gas increases when it is heated at constant volume.
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State the two assumptions of the ideal gas model that are least valid at very high pressure, and explain why.
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Calculate the volume, in m³, occupied by 2.00 mol of an ideal gas at 300 K and 250 kPa. (R = 8.31 J K⁻¹ mol⁻¹)
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State what is meant by molar volume and give its value at STP, explaining why it is the same for all gases.
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A 5.00 dm³ vessel contains a gas at 101 kPa and 298 K. Calculate the amount of gas, in mol. (R = 8.31 J K⁻¹ mol⁻¹)
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Explain why the ideal gas equation gives inaccurate results for a real gas at low temperature.
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2026
What is the volume of 2.00 mol of an ideal gas at 273 K and 101 kPa? Take R = 8.31 J K⁻¹ mol⁻¹.
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A gas occupies 250 cm³ at 100 kPa. Calculate its volume when the pressure is increased to 250 kPa at constant temperature.
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A 250 cm³ sealed flask contains argon gas at a pressure of 105 kPa and a temperature of 30.0 °C.
Calculate the amount, in moles, of argon present.
(R = 8.31 J K⁻¹ mol⁻¹.)
Calculate the amount, in moles, of argon present.
(R = 8.31 J K⁻¹ mol⁻¹.)
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A gas occupies 250 cm³ at a pressure of 120 kPa.
At constant temperature, the gas is allowed to expand to 400 cm³.
Calculate the new pressure. [2]
At constant temperature, the gas is allowed to expand to 400 cm³.
Calculate the new pressure. [2]
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2026
Outline the assumptions of the ideal gas model.
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2026
A fixed mass of gas occupies 2.0 dm³ at 27 °C. At constant pressure, what volume does it occupy at −73 °C?
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A 1.50 dm³ sample of gas is at 100 kPa and 27 °C.
It is heated to 177 °C and at the same time compressed to 1.00 dm³.
Calculate the new pressure, in kPa. [3]
It is heated to 177 °C and at the same time compressed to 1.00 dm³.
Calculate the new pressure, in kPa. [3]
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