20 mL of a solution os sulphuric acid neuitralise 21.2 mL of 30% soution of sodium carbonete. How much water should be added to 100 mL of this solutio to bring down its down its strength to decinoral?

Explanation

Calculation of normality of suplhric acid solution
strength of `Na_(2)CO_(3)` solution=`130g//100mL =300gL^(-1)`
` "Normality of" Na_(2)CO_(3) "solution"=("Strength")/("Equivalent mass")= (300gL^(-1))/(53g equiv^(-1))`
`=5.66"equiv." L^(-1)=5.66 N`.
`N_(1)xxV_(1)=N_(2)xxV_(2)or N_(1)=(N_(2)xxV_(2))/V_(1)`
`(H_(2)SO_(4))=(Na_(2)CO_(3))`
`N_(1)=((5.66N)xx(21.2mL))/((20.0mL))=6.0N`.
Calculation of volume of water to be added
Normality of `H_(2)SO_(4)` solution=6.0N
volume of `H_(2)SO_(4)` solution=100mL
Normality of diluted `H_(2)SO_(4)` solution=0.1N
Volume of diluted `H_(2)SO_(4)` solution may be calculated as:
`"underset"(("diluted" H_(2)SO_(4)))(N_(1)xxV_(1))=underset(("Concentreated"H_(2)SO_(4)))(N_(2) xx V_(2))`
`V_(1)=(N_(2)xxV_(2))/N_(1)=((6.0N)xx(100mL))/((0.1N))=6000mL`
Volume of water to be added =(6000-100)=5900mL