DP Physics (last assessment 2024)

Question 18M.3.SL.TZ2.7d.ii

Date	May 2018	Marks available	[Maximum mark: 1]	Reference code	18M.3.SL.TZ2.7d.ii
Level	SL	Paper	3	Time zone	TZ2
Command term	Outline	Question number	d.ii	Adapted from	N/A

d.ii.

[Maximum mark: 1]

18M.3.SL.TZ2.7d.ii

A cylinder is fitted with a piston. A fixed mass of an ideal gas fills the space above the piston.

M18/4/PHYSI/SP3/ENG/TZ2/07._01

The gas expands isobarically. The following data are available.

$\begin{array}{*{20}{l}} {{\text{Amount of gas}}}&{ = 243{\text{ mol}}} \\ {{\text{Initial volume of gas}}}&{ = 47.1{\text{ }}{{\text{m}}^3}} \\ {{\text{Initial temperature of gas}}}&{ = -12.0{\text{ °C}}} \\ {{\text{Final temperature of gas}}}&{ = + 19.0{\text{ °C}}} \\ {{\text{Initial pressure of gas}}}&{ = 11.2{\text{ kPa}}} \end{array}$

The gas returns to its original state by an adiabatic compression followed by cooling at constant volume.

(d.ii)

Outline the change in entropy of the gas during the cooling at constant volume.

[1]

Markscheme

energy is removed from the gas and so entropy decreases

temperature decreases «at constant volume (less disorder)» so entropy decreases

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Option B: Engineering physics

Option B: Engineering physics » Option B: Engineering physics (Core topics) » B.2 – Thermodynamics

Option B: Engineering physics » Option B: Engineering physics (Core topics)

Question 18M.3.SL.TZ2.7d.ii

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