Question

Calculate the molarity of Naoh in the solution prepared by dissolving 8g in enough water to form 500 ml of the solution. Given molecular mass. Of naoh 40g/mol

Answer 1

molecular mass = 40g/mol
mass of NaOH =8g
volume of solutions =500ml
1ml =0.001 litre
now, volume of solution(in L) =0.001*500=0.50L

Molarity (M) = Mass of NaOH / Molar mass of. NaOH/ Volume of solution (in L)

= (8g/40g)/0.50L
= 0.2mol/0.50L
= 0.4M

Answer 2

Given :

Mass of the solute = 8 gm

Volume of the solution = 500 ml = 0.5 L

To Find :

Molarity of NaOH

Solution :

Molarity of a solution can be defined as the number of gram-moles of the solute present in 1 L of the solution.

Molarity = $\frac{Moles Of Solute }{Volume Of Solution}$

No. of moles of NaOH = $\frac{8}{40}$ = 0.2 moles

∴ Molarity of NaOH solution  = $\frac{Moles Of Solute}{Volume Of Solution}$

                                                  = $\frac{0.2}{ 0.5}$

                                                  = 0.4 M

Therefore, the molarity of the solution prepared by dissolving 8g NaOH in water to form 500 ml solution is found to be 0.4 M.