The difference in the rates of reaction of large lumps and of small lumps of calcium carbonate depends on the surface area to volume ratios of the lumps.
Figure 1 shows a cube of calcium carbonate.
a.[3]
Calculate the surface area to volume ratio of the cube in Figure 1. Give your answer as the simplest whole number ratio in the form surface area:volume\text{surface area} : \text{volume}surface area:volume.
b.[2]
A larger cube of calcium carbonate has sides of 2 cm2\text{ cm}2 cm.
Describe how the surface area to volume ratio of this larger cube differs from that of the cube shown in Figure 1.