Physics
End of chapter questions Getting started 1
Label these diagrams as solid, liquid and gas.
1 Mark
2
Describe how these models represent a solid, liquid and gas.
2 Marks
3
Give the state that a gas turns into when it condenses.
1 Mark
4
Describe how energy is needed to change the state of a substance.
1 Mark
5
Write the relationship between mass, volume and density.
1 Mark
6
An object has a mass of 100 g and a volume of 25 cm . Calculate its density.
1 Mark
7
The specific latent heat of fusion of water = 340 000 J/kg. Explain carefully what this means.
2 Marks
Calculate the amount of energy needed to change the temperature of 2 kg of water by 10 °C using the equation ∆E = mc∆q . The specific heat capacity of water is 4200 J/kg°C.
1 Mark
8
3
Going further How do we describe the energy that equals the total kinetic and potential energies of the particles in a substance?
1 Mark
10
Explain why there are two different latent heats for each substance.
1 Mark
11
What is meant by the internal energy of a system?
2 Marks
12
2.0 kg of water was placed in a saucepan and heated to 100 °C. The water then completely boiled into steam.
9
13
48
Here is some data about water and steam:
density of water = 1000 kg/m3
density of steam = 0.59 kg/m3
The latent heat of vaporisation of water = 2 260 000 J/kg
a Explain why the density of steam is much smaller than the density of the water.
1 Mark
b Calculate the volume of the steam that was produced once all of the water had boiled.
1 Mark
c The pressure of the steam was 1.5 × 105 Pa. As the steam rises up, the pressure reduces to 1.0 × 105 Pa. Use your answer to part b to calculate the new volume of the steam.
1 Mark
d Use the equation E = mL to calculate how much energy was needed to boil the water into steam at 100 °C.
1 Mark
Water in an ice cube tray is put into a freezer. Explain what happens the energy stored inside the system.
2 Marks
OCR Gateway GCSE Physics: Student Book
50969_P012_049.indd 48
8/11/16 7:34 AM