Question

22.7 ml of N/10 Na2CO3 solution neutralises 10.2 ml of a dilute H2SO4. Then the volume of water that must be added to 400 ml of same H2SO4 to make it exactly N/10 is??
Answer is 400 ml. Can you please explain with steps? Thanks.

Answer 1

Hello Dear. ↔

Number of equivalent must be the same , Let normality of H₂SO₄ = N .

Now finding the number of equivalent where equivalent in both of the solution must be same

∴ 0.1 × 22.7 = N × 10.2
N= $\frac{0.1 x 22.7 }{10.2}$
N= 0.2225

Now, The number of equivalent present in the 400ml of solution =

→ = N × 400 ml
= 0.2225 × 400
= 89 mili equivalent.

Now , For making the solution of 0.1 N , Let the volume of solution be V.
→ 0.1 × V = 89
V= $\frac{89}{0.1}$
V = 890 ml .
Hence according to question, The volume of water that must be added is 400 ml.
∴v = 890 -400
→V = 490 ml. ←

So your answer 400 ml is incorrect ,The correct answer is 490 ml.

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Hope it helps.

Have a nice day