10g of a solid substance is placed in a 20 mL flask and its

10g of a solid substance is placed in a 20 mL flask and its remaining volume is filled with water (assume that the solid is not soluble in water). Together the solid and water weigh 27.2 g. If the density of water is 1 g/cm3 what is the density of the solid substance?

Solution

Weight of the solid = 10g

Together the solid and water weigh = 27.2 g

So, the weight of the water in the flask = 27.2-10=17.2 g

The volume of the water in the flask = 17.2 x 1 = 17.2 mL

Total volume of the flask = 20 mL

So, the volume of the solid = 20- 17.2 = 2.8 cm³

So, the density of the solid substance = 10/2.8 = 3.57 g/cm³