Question

When is the density of water `"1 g/mL"`? How can we measure density?

Answer 1

`(1 g)/(1 mL)`

Explanation:

The density of pure water is 1 gram per 1 milliliter or one cubic cm. By knowing the density of water we can use it in dilution equations or to calculate the specific gravity of other solutions.

It can also help us determine what other substances are made of using the water displacement experiment. This is done by observing how much water is displaced when an object is submerged in the water. As long as you know the density of the water, the mass of the object being submerged and the volume of increase you can calculate the density of the object.

This was done by the great Archimedes in discovering what composed the kings crown.

Answer 2

The density of water at `25^@"C"` is `0.997074"9 g/mL"`. It is only `"1 g/mL"` near `4^@"C"`. By using the volume displaced of water as indicative of a particular solid's density in relation to its mass, the density of the solid can be determined.

EX:

If `"5 mL"` of water is displaced when `"10 g"` of solid is placed in the water, then it is a relatively good assumption that the density of the solid is `"2 g/mL"`.