2023 · M/J · 5054/22 | Q3

0/46parts marked · 0 of 76 available marks

Question (3 of 10)9 marks · Practise this topic →

Options

Available practice: 76 of 80 marks. Parts 10(c) await marking support. Scores cover available parts only. Theory: answer each printed part. For drawings, upload a clear photo of your sketch on the supplied figure; show working and units for calculations.

A fixed mass of gas in a glass tube is trapped by a seal at one end and by a column of mercury. The tube is rotated slowly from vertical (Fig. 3.1) to horizontal (Fig. 3.2). The gas volume increases while its temperature remains constant.

(a)(i)Describe why rotating the tube changes the pressure of the gas at its sealed end.

Fig. 3.1 — see the question text for what it shows

Fig. 3.2 — see the question text for what it shows

Answer guidance

Describe Say what happens, in order. Reasons are not required unless the question also asks why.

[1 mark]

(a)(ii)Explain, using ideas about particles, why gas pressure decreases when its volume increases at constant temperature.

Answer guidance

Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.

[3 marks]

(b)In Fig. 3.1 the mercury column is 0.30 m long. Mercury density is 14 000 kg/m³ and atmospheric pressure is 1.0 × 10⁵ Pa. Calculate the gas pressure.

Answer guidance

Calculate Show your working. The method can earn marks even when the final value is wrong, and a bare answer often cannot.

[3 marks]

(c)Fig. 3.3 shows X at pressure P₀ and volume V₀ for a different gas at constant temperature. On Fig. 3.3 sketch pressure against volume as pressure falls from 2P₀ to ½P₀.

Fig. 3.3 — see the question text for what it shows

[2 marks]

5054/22/M/J/23Cambridge O Level Physics 5054 · May/June 2023 · Paper 2 variant 2 · Question 3