6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
Learn this properly: Density of MaterialsA sealed flask contains a fixed mass of water. The water is heated from ice at −10 ∘C, through liquid water, until it becomes steam.
Describe and explain, using the particle model, how the arrangement, movement and energy of the water particles change as the water is heated through its solid, liquid and gas states, including what happens at melting and boiling. Explain why the temperature stays constant during each change of state. (6 marks)
A student measures the density of a small metal cube. The cube has sides of length 2.0 cm, and its mass is measured on a balance as 62.4 g.
(a) Calculate the volume of the cube in cm3. (1 mark)
(b) Calculate the density of the metal in g/cm3. Use ρ=Vm. Show your working and give the unit. (2 marks)
(c) State one way the student could find the volume of an irregularly shaped object instead. (1 mark)
A kettle contains 0.50 kg of water. The water is heated so that its temperature rises from 20 ∘C to 90 ∘C.
The specific heat capacity of water is 4200 J/kg ∘C.
Calculate the energy transferred to the water. Use E=mcΔθ. Show your working and give the unit. (3 marks)
A heater supplies energy to melt a block of ice that is already at its melting point of 0 ∘C. To melt the block completely, 68 000 J of energy is transferred, and the mass of ice melted is 0.20 kg.
(a) Calculate the specific latent heat of fusion of ice. Use E=mL. Show your working and give the unit. (2 marks)
(b) State what happens to the temperature of the ice–water mixture while the ice is melting, and explain why. (1 mark)
A sealed, rigid metal container holds a fixed mass of gas. The container is left in the sun and the gas inside becomes hotter. The volume of the container does not change.
Explain, using the particle model, why the pressure of the gas inside the container increases as its temperature rises. (2 marks)
A physical change, such as melting or boiling, does not change the mass of a substance.
State what is meant by saying mass is conserved during a change of state, in terms of the particles. (1 mark)