as?","back":"

Low density
Particles far apart compared to their size

","points":2,"mcqOptions":[{"text":"

Low density
Particles far apart compared to their size

","correct":true,"explanation":"At low density, the particles are widely separated relative to their size, so particle volume and intermolecular forces have negligible effects on the gas’s behaviour."},{"text":"

High density
Particles close together compared to their size

","correct":false,"explanation":"High density forces particles close together, making their finite volume and intermolecular forces significant. Ideal behaviour is approached at low density, when particles are far apart relative to their size."},{"text":"

Low temperature
Attractive forces large compared to their energy

","correct":false,"explanation":"Low temperature makes attractive intermolecular forces more important, increasing deviation from ideal behaviour. A real gas behaves most ideally at low density, with particles far apart relative to their size."},{"text":"

High pressure
Particle volume comparable to the gas’s volume

","correct":false,"explanation":"High pressure compresses a gas, so the particles’ own volume is no longer negligible. Ideal behaviour requires low density and separations much greater than the particles’ size."}]},{"id":"295ad786-a32f-4faa-81d0-c171c74515f1","cardType":"basic","front":"State the formula relating the number of particles $N$ to the amount of substance $n$.","back":"$$N = nN_A$","points":1,"mcqOptions":[{"text":"$$N = nN_A$","correct":true,"explanation":"Each mole contains $N_A$ particles, so multiplying the amount of substance $n$ by Avogadro’s constant gives the total number of particles $N$."},{"text":"$$N = \\frac{n}{N_A}$","correct":false,"explanation":"Dividing by Avogadro’s constant reverses the required conversion. Each mole contains $N_A$ particles, so the correct relationship is $N = nN_A$."},{"text":"$$N = \\frac{N_A}{n}$","correct":false,"explanation":"This incorrectly makes the particle number decrease as the amount of substance increases. The quantities are directly proportional, giving $N = nN_A$."},{"text":"$$N = nR$","correct":false,"explanation":"This confuses the molar gas constant $R$ with Avogadro’s constant $N_A$. Converting moles to particles requires $N = nN_A$."}]}]}],"examCountdown":{"examDate":"2027-05-21","paperLabel":"Paper 1"},"heading":"Ideal gases","title":"Ideal gases Flashcards","topicSidebar":"$L3f"}]}],"topicId":"be6bf530-bf10-50e1-8270-ea20cb1b96db","walled":"$L40"}],"$L41"]