O-LevelPhysicsThermal Physics5054/21 · May/June 2015 · Q36 Marks
An experiment is carried out to find how the pressure of a fixed mass of air at room temperature varies with volume. Fig. 3.1 shows the apparatus used. The syringe is sealed at one end and the piston is free to move up and down as different metal weights are used. Fig. 3.2 shows the axes for a graph of pressure against volume for the air in the syringe. One point is plotted on the graph at pressure of P₀ and volume V₀. The temperature of the air is kept constant. [Figure 3.1] [Figure 3.2]
- (a)State the unit in which pressure is measured.[1]
- (b)(i)plot points at volumes of 0.5 V₀ and 2.0 V₀,[1]
- (b)(ii)complete the graph.[1]
- (c)More metal weights are placed on top of the syringe. Explain how the molecules of air inside the syringe are able to support more metal weights.[3]
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
Mark scheme
Marking points from the official mark scheme (May/June 2015). The mark or mark type is shown in brackets.
- [1] Pa or N/m² or cm of mercury or atmosphere(s)
- [1] correct points plotted at (0.5V₀, 2P₀) and (2V₀, 0.5P₀)
- [1] curve through points of decreasing gradient
- [1] molecules hit sides/piston
- [1] more molecules hit per second/hit more frequently
- [1] molecular impacts create large(r) force (upwards on piston)
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →