Help me work out density please!!

Question

If you dissolve 52.5 g of salt in 3.45 l of water, what is the density of that solution of salty water? In this particular example, assume that the total volume doesn’t change when salt is added to water. You will need the mass of salt and the mass of water to find the mass of the solution of salty water. Don’t forget to show your working and include SI units.

Answer 1

So, density is defined as mass per unit volume. This is generally given as grams per milliliter. So, we will find the grams (mass) and the volume (mls) and then determine density.

mass of salt = 52.5 g

mass of water = 3.45 L x 1000 ml /L = 3450 ml and if we use 1.0 g/ml as the density of water, we have 3450 g

Total mass of salt plus water = 52.5 g + 3450 g = 3502.5 g

Total volume in mls = 3450 mls

Density = mass/volume

Density = 3502.5 g / 3450 mls

Density = 1.02 g/ml (to 3 significant figures)