ibo.org
Updates to Questionbank

User interface language: English | Español

« Back to questions in DP Physics

Date May 2015 Marks available 3 Reference code 15M.2.SL.TZ1.3
Level Standard level Paper Paper 2 Time zone Time zone 1
Command term Question number 3 Adapted from N/A

Question

This question is about thermal properties of matter.

Explain, in terms of the energy of its molecules, why the temperature of a pure substance does not change during melting.

[3]
a.

Three ice cubes at a temperature of 0°C are dropped into a container of water at a temperature of 22°C. The mass of each ice cube is 25 g and the mass of the water is 330 g. The ice melts, so that the temperature of the water decreases. The thermal capacity of the container is negligible.

The following data are available.

Specific latent heat of fusion of ice \( = \) 3.3 \( \times \) 105J kg–1

Specific heat capacity of water \( = \) 4.2 \( \times \) 103 J kg–1 K–1

Calculate the final temperature of the water when all of the ice has melted. Assume that no thermal energy is exchanged between the water and the surroundings.

[4]
b.

Markscheme

energy supplied/bonds broken/heat absorbed;

increases potential energy;

no change in kinetic energy (so no change in temperature);

a.
use of M \( \times \) 4.2 \( \times \) 103 \( \times \) ∆θ 
ml \( = \) 75 \( \times \) 10–3 \( \times \) 3.3 \( \times \) 105 / 24750 J;
recognition that melted ice warms and water cools to common final temperature;
3.4ºC;

b.

Examiners report

[N/A]
a.
[N/A]
b.

Syllabus sections

Core » Topic 3: Thermal physics » 3.1 – Thermal concepts
Show 97 related questions
Hide related questions

View options

Ib logo tri med

© International Baccalaureate Organization 2018
International Baccalaureate® - Baccalauréat International® - Bachillerato Internacional®

Printed for IB Documents Team