What will be the molarity of a solution, which contains 5.85 g of NaCl(s) per 500 mL? (i) 4 mol L-1 (ii) 20 molL-1 (iii) 0.2 molL-1 (iv) 2molL-1

Correct Answer: (iii) 0.2 molL^-1

Explanation: The Molarity is defined as the number of moles per volume of the solution in litres.

Given,

Mass = 5.85g

Molar mass = 58.5 g/mol

Volume of the solution = 0.5 L

So,

Number of moles = mass/molar mass

Number of moles =5.85/58.5

Number of moles =0.1 mol

Hence,

Molarity = 0.1/0.5

Molarity = 0.2mol/L