S1.5 Ideal gases
15 revision questions with answers for S1.5 Ideal gases, marked SL. Read them here, or play the set as a class game on the projector. Free to host, and students join with a code.
In the ideal gas model, the volume of the particles themselves is…?
- Significant
- Constant
- Variable
- NegligibleRight answer
What this set covers
Ideal gas behaviour from model assumptions to calculation: negligible particle volume, no attractions, deviations at high pressure and low temperature, molar volume at STP, gas laws and PV = nRT.
- Common mix-up
- Students often forget the units when using PV = nRT: with pressure in Pa and R = 8.31, volume must be in m³, so 1.0 dm³ becomes 1.0 × 10⁻³ m³.
- Revision tip
- Pick one gas-law question and solve it twice, once with PV = nRT and once with the proportionality, to see that both routes agree.
All 15 questions and answers
In the ideal gas model, the volume of the particles themselves is…?
Answer: Negligible
Forces of attraction between particles in an ideal gas?
Answer: None
Collisions between particles in an ideal gas are…?
Answer: Perfectly elastic
Conditions under which real gases deviate most from ideal behaviour?
Answer: High pressure, low temperature
Molar volume of an ideal gas at STP (273 K, 100 kPa)?
Answer: 22.7 dm³ mol⁻¹
Volume of 2.0 mol of gas at STP (molar volume 22.7 dm³ mol⁻¹)?
Answer: 45.4 dm³
Amount of gas in 4.54 dm³ at STP (molar volume 22.7 dm³ mol⁻¹)?
Answer: 0.200 mol
At constant temperature, doubling a gas's pressure makes its volume…?
Answer: Halve
At constant pressure, 1.0 dm³ of gas heated from 200 K to 400 K occupies…?
Answer: 2.0 dm³
At fixed volume and amount, gas pressure is directly proportional to…?
Answer: Kelvin temperature
The ideal gas equation?
Answer: PV = nRT
Value of the gas constant R in J K⁻¹ mol⁻¹?
Answer: 8.31
Unit of volume needed in PV = nRT when pressure is in Pa?
Answer: m³
1.0 dm³ expressed in m³?
Answer: 1.0 × 10⁻³ m³
Quantity that stays constant for a fixed amount of gas as P, V and T change?
Answer: PV/T
Play it as a class game
Play this set opens it in splycr, where you can host it for your class straight away. Hosting needs no account: put the room code on the projector, and students join from a phone with the code and their first name. Each question plays as multiple choice, and the three wrong options were written for that question.