Question

Whether the statement is true or false
$10%$ ${NaCl}$ means: \[10{ }gm\] of \[NaCl\] in \[100mL\] of solution.

Answer 1

Hint: In chemistry the concentration of a solution is the quantity of solute that is contained in particular quantity of solvent or solution. Knowing the concentration of solutes is important in determining the stoichiometry of reactions for solutions. Since ${NaCl}$ is a solid substance so we cannot consider it as $(\dfrac{v}{v})$% . So we can consider it as $(\dfrac{w}{v})$%.

Complete step by step answer:
Mass by volume percentage, mass by mass percentage and volume by volume percentage are the terms used to express the concentration for the reactions that take place in the solutions. Mass by volume percentage means a particular amount of solute in grams is dissolved per \[100mL\] of solution .Volume by volume percentage depicts that a particular volume of any liquid is dissolved per \[100mL\] of solution and mass by volume percentage means a particular amount of solute is dissolved per \[100mL\] of solution.
Since ${NaCl}$ is a salt so we cannot express the concentration in terms of volume by volume percentage. Hence we consider the concentration in terms of mass by volume percentage.
So, if we consider the question it is given that $10%$ ${NaCl}$ which means \[10{ }gm\] of ${NaCl}$ is dissolved in \[100mL\] of solution.

So, the given statement is true.

Note: There are also many different units of concentration. The standard unit of concentration in the field of chemistry is molarity. It can be defined as the number of moles of solute dissolved per litre of solution. Always keep in mind about the nature of solute whether it is liquid or solid if we have to express the concentration for the reactions in solutions.