500 " mL of " 1.0 M `H_2C_2O_4`, 100 " mL of " 2.0 M `H_2SO_4`, and `40 g` of `NaOH` are mixed together, 30 " mL of " the above mixture is titrated against a standard solution of sodium carbonate containing 14.3 g of `Na_2CO_3.10H_2O` per 100 " mL of " solution. Find the volume of carbonate solution used for complete neutralisation.

Explanation

m" Eq of "`H_2C_2O_4=2xx1.0xx500=1000`
m" Eq of "`H_2SO_4=2xx2.0xx100=400`
m" Eq of "acid(s) `=1400`
Now m" Eq of "NaOH (base) `=(Wt.)/(Ew)xx100`
`=(40)/((40)/(1))xx1000=1000`
Excess of acid/30 mL in the mixture `=400`
So m" Eq of "acid`=`m" Eq of "carbonate
Normality of cabonate`=("strength")/(E)(143)/((286)/(2))`
`((14.3)/(100mL)-=143gL^(-1))`
`N=1`
m" Eq of "acid (excess)/30 mL`=(30)/(600)xx400=20`
`implies20=NV`
`impliesV=20 mL` of carbonate