1 / 1
aqa a level physics paper 2
1. what is meant by specific heat capacity <Ans> the energy needed to
raise the temperature of 1kg of material by 1C.
2. define avogadro's constant <Ans> the number of atoms in 12g of carbon 12
(OR the no. of particles/atoms in one mole of a substance)
3. define the specific latent heat of vaporisation of water <Ans> the energy
required to change the state of a unit mass of water to gas (1) without a change in
temperature (1)
4. features of an ideal gas (3) <Ans> - collisions are elastic
- molecules have negligible volume
- gas obeys ideal gas law (Boyles law)
5. assumptions made in the molecular kinetic theory of an ideal gas
<Ans> - all molecules are identical
- molecules in random motion
- newtonian mechanics apply
- vol of gas molecules negligible (compared to vol of gas)
- collisions are elastic
6. state and explain what happens to the speed of molecules in a gas when
the temperature increases <Ans> the average/mean speed of molecules
increases (1) as mean ke proportional to absolute temp
7. state what is meant by an elastic collision <Ans> a collision in which ke is
conserved
8. two different gases at the same temp have molecules with different mean
square speeds. explain how this is possible <Ans> masses are different (1)
