Physics 5054 · O Level · Melting, boiling and evaporation
Melting, boiling and evaporation — practice question
In many countries, solid salt is made by holding sea-water in large, shallow ponds and leaving the water to evaporate away. Fig. 4.1 illustrates salt being produced in this manner.
(a)[2]
State two differences between evaporation and boiling.
(b)[2]
Describe, using water molecules, what is happening as the water evaporates.
(c(i))[1]
State why the ponds in this process have large surface areas.
(c(ii))[1]
State why this salt-production method is not effective in a country with a cold climate.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Happens only at the surface / no bubbles form” …