Question

What is the molarity of a 6.3 g HNO3 and 100 ml solution? [H=1 N=14 O=16] [5.20] ​

Answer 1

we have to find the molarity of a 6.3 g HNO₃ and 100 ml solution.

solution : first we should find the molecular weight ofd HNO₃.

molecular weight of HNO₃ = atomic weight of H + atomic weight of N + 3 × atomic weight of O

= 1 + 14 + 3 × 16

= 15 + 48

= 63 g/mol

now the number of moles of HNO₃ in 6.3 g = given weight of HNO₃/molecular weight of HNO₃

    = 6.3 g/(63 g/mol)

    = 0.1 mol

we know, the molarity of a solution is the number of moles of solute in one litre of solution.

∴ molarity of solution = no of moles of solute(HNO₃)/volume of solution

                                   = 0.1/(100/1000) = 1 M

therefore the molarity of the solution is 1 M.