Question

To make a saturated solution $36g$ of sodium chloride is dissolved in $100g$ of water to find the concentration of solution.

Answer 1

Hint : We know that there are three different ways in which we can describe concentration; however, mass of solute and mass of solvent is given in the question, therefore, concentration will be the mass of solute divided by the mass of solution.

Complete Step By Step Answer:
As we can see in the question, mass of solute and mass of solvent is given in the question. So, we will have to calculate the mass percentage of the solution. Also, we should know about what the saturated solution is. It is a solution at which the maximum amount of solute that can be dissolved under the particular temperature and pressure at which the solution exists. Mass Percentage: When mass of both the solute and the solvent is given in grams, it is always convenient to express the concentration in terms of Mass percentage.
Also, if temperature increases, solubility also increases and if it decreases solubility also decreases. It infers that solubility is directly proportional to the temperature.
Mass of Solute (Sodium Chloride) $=\text{ }36g$
Mass of Solvent (Water) $=\text{ }100g$
$Mass\text{ }of\text{ }Solution\text{ }=\text{ }Mass\text{ }of\text{ }Solute\text{ }+\text{ }Mass\text{ }of\text{ }Solvent$
$\therefore Mass\text{ }of\text{ }Solution\text{ }=36+100g=136g$
Thus, $Concentration\text{ }of\text{ }solution\text{ }=\text{ }Mass\text{ }of\text{ }Solute\text{ }\div Mass\text{ }of\text{ }Solvent\text{ }\times \text{ }100$
$\therefore Concentration\text{ }of\text{ }solution\text{ }=\dfrac{36}{136}\times 100=26.47$
Therefore, to make a saturated solution $36g$ of sodium chloride is dissolved in $100g$ of water the concentration of solution is $26.47$ .

Note :
Remember that never forget to mention the unit of mass percentage i.e. $w/w\text{ }or\text{ }v/v\text{ }or\text{ }w/v.$ the sodium chloride solution in water is homogeneous in nature. Also, the above reaction is endothermic in nature which means it absorbs energy from the surroundings.