chem 1 please help

Question

A chemist has a block of iron metal (density is 7.87 g/mL). The block weighs 2.70 g. What is the volume of the iron block in mL?

Answer 1

Use dimensional analysis:

2.70 g x 1 ml / 7.87 g (note that the units of g will cancel leaving you with units of ml)

2.70 g x 1 ml / 7.87 g = 0.343 mls

If you wish to set up a proportion, you would have the following;

7.87 = 1 ml ... as 2.70 g = x ml

7.87 g / 2.70 g = 1 ml / x ml

x = 0.343 mls