Question

The density of ice is $0.921gc{m^{ - 3}}$ . Calculate the mass of a cubic block of ice which is $76mm$ on each side.
A.$49g$
B.$4 \times {10^2}g$
C.$0.04g$
D.$4 \times {10^3}g$

Answer 1

Hint:Water is a substance made up of two molecules of hydrogen and one molecule of oxygen. It is the most essential substance. It exists in all three states- solid, liquid and gas. Density is defined as a measure of mass per volume of a substance.
Formula used: $density = \dfrac{{mass}}{{volume}}$

Complete step by step answer:
We know that $1mm = 0.1cm$
$ \Rightarrow 76mm = 7.6cm$
Volume of a cube = $sid{e^3}$
$ \Rightarrow V = {(7.6)^3}$
$ \Rightarrow V = 438.98c{m^3}$
According to the formula of density
$density = \dfrac{{mass}}{{volume}}$
$\therefore mass = density \times volume$
$ \Rightarrow m = 0.921 \times 438.98$
$ \Rightarrow m = 404g = 4.04 \times {10^2}g$

So, the correct answer is option (B).

Note:
Water is a substance made up of two molecules of hydrogen and one molecule of oxygen. It is the most essential substance that helps sustain life. It is tasteless and odourless and is used to dissolve many
compounds which form hydrogen bonding with its molecules. The molecular formula of water is ${H_2}O$ .
It is polar in nature and is considered as the universal solvent. It has high heat capacity and high heat of vapourization. Water exists in all three states- solid, liquid and gas and it is less dense as a solid than as a liquid because as water freezes, the water molecules move apart from each other. Ice is an inorganic compound which has a crystalline structure.
Density is defined as a measure of mass per volume of a substance. A substance which is denser than water sinks in water and a substance which is less dense floats on the water surface. Density is calculated as the ratio of mass and volume.
$density = \dfrac{{mass}}{{volume}}$
Liquids and gases are those forms of matter which are known as fluids as they have the tendency to flow. This fluidity is due to the property of the molecules of liquids and gases to move freely. Whereas the particles of solids are tightly packed and have fixed positions and thus, they are rigid.