Question

Calculate molarity of solution if 5.85 gram of sodium chloride is dissolved to make 250 ml of solution.

Answer 1

Solution :

Given :-

Mass of sodium chloride = 5.85g

Volume of solution = 250ml

To Find :-

Molarity of solution

Concept :-

Molarity is defined as ratio of moles of solute to the volume of solution.

Molarity shows concentration of solute in solution.

Mathematically,

$\underline{\boxed{\bf{\purple{M=\dfrac{W_{solute}\times 1000}{Mw_{solute}\times Vml_{solution}}}}}}$

Chemical formula = NaCl

Molecular weight = 58.5g/mol

Calculation :-

$\implies\sf\:M=\dfrac{5.85\times 1000}{58.5\times 250}\\ \\ \implies\sf\:M=\dfrac{4}{10}\\ \\ \implies\underline{\boxed{\bf{\purple{\large{M=0.4\:molL^{-1}}}}}}$

Answer 2

Answers

Molarity is the number of moles present in 1 litre of a solution. It can also be defined as the ratio of moles of the solute to the volume of solution.

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Given mass of solute = 5.85 gram

Volume of the solution= 250 mL

Mass of sodium chloride (NaCl) = (23+17.5)=58.5 gram.

Therefore,

$Molarity = \frac{mass \: of \: solute \times 1000}{molecular \: mass \times volumne(ml)}$

$Molarity = \frac{5.85 \times 1000}{58.5 \times 250}$

$Molarity = \frac{4}{10} = 0.4mol \: per \: litre$

Therefore, Molarity of the solution is 0.4mol L¯¹.