A student heats a liquid. While it boils, the temperature rises steadily from 78 ∘C78\,^\circ\mathrm{C}78∘C to 85 ∘C85\,^\circ\mathrm{C}85∘C instead of staying at one temperature. What is the best explanation?
The mass of liquid is too large to boil at once
Heat is being lost to the surroundings
The liquid is a mixture of substances
Covalent bonds in the molecules are breaking
84 exam-style questions on Edexcel GCSE Chemistry 3.1 States of matter, covering 3.1.1 The three states of matter and changes of state. Each one has a worked solution and a mark scheme showing where the marks go.