Question

A metal object has a mass of 8.37g. When it was in a graduated cylinder containing 20.0 ml of water, the water level rose to 23.1 ml. What is the density and identity of the metal

Answer 1

Mass of metal is 8.37 g, volume of water in graduated cylinder is 20 mL. After adding the metal, water level increases to 23.1 mL. The volume of metal is equal to the increase in water level.

The increase in water level can be calculated by taking difference of final and initial level of water.

Thus,

$V_{metal}=V_{f}-V_{i}=(23.1-20)mL=3.1 mL$

Density of metal is defined as mass per unit volume of metal. It can be calculated as follows:

$d=\frac{m}{V}=\frac{8.37 g}{3.1 g/mL}=2.7 g/mL$

This value corresponds to the density of aluminum.

Therefore, density is 2.7 g/mL and metal is aluminum.