(a)[1]
Define what is meant by pressure.
(b(i))[1]
Explain why both sides of the manometer in Fig. 8.1 have the same water level.
(b(ii))[1]
Explain why opening the gas tap while the manometer is connected as in Fig. 8.2 causes the water levels to change.
(b(iii))[1]
Explain why the water levels come to rest at the positions shown in Fig. 8.2.
(c)[4]
Calculate the pressure of the gas trapped inside the sealed container. Give your answer to 3 significant figures.
(d)[4]
Using ideas about molecules, explain why the water levels alter.
(e(i))[2]
Explain why this manometer would not be suitable for measuring a gas pressure of $2.5 \times 10^5\,\text{Pa}$.
(e(ii))[1]
State one modification to this manometer that would let it measure a gas pressure of $2.5 \times 10^5\,\text{Pa}$ in a normal school laboratory.