Question

Two students decided to investigate the effect of water and air on iron object under identical experimental conditions. They measured the mass of each object before placing it partially immersed in 10 ml of water. After a few days, the object were removed, dried and their masses were measured. The table shows their results.

Student	Object	Mass of Object before Rusting in g	Mass of the coated object in g
A	Nail	3.0	3.15
B	Thin plate	6.0	6.33

What might be the reason for the varied observations of the two students?

Answer 1

Rusting occurs in both A and B so there is an increase in mass. As the surface area of B is more, extent of rusting is more.