Question

Calculate volume of .4Molar NaOH required to react with following mixture (HCl[1mol] H2SO4 [2mol] ?

Answer 1

The mixture contains two mole sulphuric acid. Each sulphuric acid will take two NaOH for neutralisation in according to the equation
2NaOH+H2SO4 --> Na2SO4 + 2H2O
So number of moles of NaOH required= 2x2mol= 4mole
Similarly the mixture contains one mole HCl. Each HCl will take one mole of NaOH for neutralisation in according to the equation.
NaOH + HCl --> NaCl + H2O
So the number of NaOH required = 1mole
Total moles of NaOH required = 4mole + 1mole = 5mole
molarity of the solution = 0.4M
Molarity = moles/ volume
On substituting
0.4= 5 moles/volume
Volume = 5/0.4 = 12.5 litres
So the volume of NaOH required is 12.5 litres
(I assumed that the concentration of NaOH is 0.4 molar)