Two acids A and B are titrated separately each time with 25 " mL of " `N-Na_(2)CO_(3)` solution to requrie 10 mL and 40 mL respectively, of their solution for complete neutralisation. What volume of A and B would you mix to produce 1 L of N-acid solution?

Answer

4

Explanation

Let the normality of acid solution A be `N_(A)` and the normality of acid solution B be `N_(B)`
`N_(A) xx V_(A) = N_(Na_(2)CO_(3)) xx V_(Na_(2)CO_(3)) , N_(A) xx 10 = = 1 xx 25 rArr N_(A) = 2.5`
Similarly `N_(B) xx V_(B) = N_(Na_(2)CO_(3)) xx V_(Na_(2)CO_(3)) , N_(B) xx 40 = 1 xx 25 , N_(B) = (5)/(8) N`
`N_(A) Y_(A) + N_(B)V_(B) = 1 xx 1, (2.5 xx V_(A)) + (5)/(8) xx V_(B) = 1, V_(A) + V_(B) = 1, V_(A) = 1- V_(B)`
So `2.5(1-V_(B)) + (5)/(8)V_(B) = 1, 2.5 - 2.5 V_(B) + 0.625 V_(B) = 1`
`rArr 1.5 = 1.875 V_(B) rArr 0.8 = V_(B) , V_(A) = 0.2` , So `(V_(B))/(V_(A)) = 4`