Question

How many moles of NaOH must be dissolved in water to make 4.0 liters of a 2.0 M solution?

Answer 1

Answer:

the case of NaOH normality and molarity is the same.

10% NaOH solution

Normality first calc equivalnt weight (ew)

ew - molecular mass expressed in grams/ basicity

NaOH ==

ew — 23 + 16+ 1 = 40/1= 40g

dissolve this in 1000 mls same as litre or 1000cc distilled water to get a 1N solution.

N/10 is a 0.1 N solution therefore 40g * 0.1 - 4g

N/10 solution - 4g NaOH dissolved in I litre water

confirm by titration using Oxalic acid and Phenolpthalein indicator light pink colour

use equation N1V1/N2V2 equal A/B

Ph is the negative log or antilog of the hydroxyl ion concentration

concentration of OH ion is the same as the basicity which is one

antilog of one to base 10 give

Ph of 13.