Question

Relative density of water is?
(A). 0
(B). 1
(C). 2
(D). Can’t be determined

Answer 1

Hint- In order to deal with this question first we will understand the basic meaning of relative density then we will proceed further by calculating the relative density by using the formula of relative density using the absolute density of water.

Formula used- $r = \dfrac{{{\rho _m}}}{{{\rho _w}}}$

Complete step-by-step answer:

Relative density- The ratio of the density for a given substance or material to the density of the reference material (mostly taken as water) is commonly known as the relative density or the specific density of the given material to the other material.
We know that Relative density of any substance is given by:
$r = \dfrac{{{\rho _m}}}{{{\rho _w}}}$
Where r = relative density of substance
${\rho _m}$ is the absolute density of substance
${\rho _w}$ is the absolute density of water
The density of water is usually taken as \[1000kg/{m^3}\] or \[1g/c{m^3}\] . This consideration makes the relative density calculation of other materials very convenient.
 Relative density of water:
$
  \because r = \dfrac{{{\rho _m}}}{{{\rho _w}}} \\
   \Rightarrow {r_w} = \dfrac{{{\rho _w}}}{{{\rho _w}}} = \dfrac{{1g/c{m^3}}}{{1g/c{m^3}}} = 1 \\
   \Rightarrow {r_w} = 1 \\
 $
Hence the relative density of water is 1.
So, the correct answer is option B.

Note- The density of water changes with respect to change in temperature. The density of the water can be easily calculated by us using the mass of water and the volume contained by that mass. As we know that the density of water is given as mass of water per unit volume. Usually for finding the relative density of any given materials, the density of water which is always known is taken as the reference. Students must remember the absolute density of water in order to solve such problems.