25 mL of a mixture of NaOH+Na_(2)CO_(3), when titrated with (N)/(10)HCl using phenolphthalein indicator required 25 mL HCl to deccolourise phenolphthalein. At this stage methyl orange was added and addition of acid was continued. The second end point was reached after further addition of 5 mL of the acid. Calculate the amount of Na_(2)CO_(3) and NaOH in one litre of the solution.

25 mL of a mixture of NaOH+Na_(2)CO_(3), when titrated with (N)/(10)HC

1.	25 mL of a mixture of NaOH+Na_(2)CO_(3), when titrated with (N)/(10)HCl using phenolphthalein indicator required 25 mL HCl to deccolourise phenolphthalein. At this stage methyl orange was added and addition of acid was continued. The second end point was reached after further addition of 5 mL of the acid. Calculate the amount of Na_(2)CO_(3) and NaOH in one litre of the solution.
Answer» SOLUTION :Between first and second end points, `NaHCO_(3)+HCl to NaCl+H_(2)CO_(3)` `5 mL (N)/(10)HCl-=(1)/(2)Na_(2)CO_(3)` present in 25 mL of a mixture or `10 mL (N)/(10)HCl-=Na_(2)CO_(3)` present in 25 mL of a mixture `-=10 mL (N)/(10)Na_(2)CO_(3)=0.053 G Na_(2)CO_(3)` Amount of `Na_(2)CO_(3)` in one litre of mixture `=(0.053)/(25)xx1000=2.12 g` `(25-5)mL(N)/(10)HCl-=NaOH` present in 25 mL of mixture `-=25 mL (N)/(10)NaOH` `-=0.08 gNaOH` Amount of NaOH in one litre of mixture`=(0.08)/(25)xx1000=3.2 g`