Question

What is the mass of $ 15ml $ of water?

Answer 1

Hint: The density of water is nearly $ 1gm{\left( {ml} \right)^{ - 1}} $ . The density can be defined as the ratio of the mass of that compound to the volume of that compound. By substituting the value of density, and volume in the below formula gives the mass of water.
 $ d = \dfrac{m}{V} $
 $ d $ is density of water
 $ m $ is mass of water
 $ V $ is the volume of water.

Complete Step By Step Answer:
Water is a chemical compound with the molecular formula of $ {H_2}O $ , it consists of one oxygen atom and two hydrogen atoms. Due to the electronegativity of hydrogen and oxygen, there is a polarity or movement of electrons. Thus, water is considered as a polar solvent.
Density gives the information about how tightly or loosely a structure was packed. It was represented by $ d $ or $ \rho $ . density is the ratio of mass of the substance to the volume of the substance.
Water has a density of nearly $ 1gm{\left( {ml} \right)^{ - 1}} $ or $ 1gm{\left( {cm} \right)^3} $ which means one gram of water occupies one millilitre of volume. Given that the volume of water is $ 15ml $ . Thus, the density of water has to be taken as $ 1gm{\left( {ml} \right)^{ - 1}} $
Substitute the values of density of water, and volume of water in the above formula.
 $ 1gm{\left( {ml} \right)^{ - 1}} = \dfrac{m}{{15ml}} $
Further simplification gives $ m = 15g $
Thus, the mass of $ 15ml $ of water is $ 15g $ .

Note:
The density of water can be expressed in different units like gram per millilitre, gram per centimetre cube, kilogram per litre, kilogram per metre cube. As the given volume is in millilitres, the density of the units must be in grams per ml and the value should be taken as $ 1gm{\left( {ml} \right)^{ - 1}} $ .