The correct option is D 100 mL
The reaction of H2SO4 reacting with 𝑁𝑎𝑂𝐻 is as follows:
H2SO4+2NaOH→Na2SO4+2H2O
For a neutralization reaction,
Milliequivalents of 𝑁𝑎𝑂𝐻 = Milliequivalents of
H2SO4
Volume of 𝑁𝑎𝑂𝐻 × Normality of 𝑁𝑎𝑂𝐻
= Volume of H2SO4 × Normality of H2SO4
We know that,
Normality=Molarity×n−factor
Volume of 𝑁𝑎𝑂𝐻 × Molarity of 𝑁𝑎𝑂𝐻 ×
𝑛 − 𝑓𝑎𝑐𝑡𝑜𝑟 = Volume of H2SO4 × Molarity of
H2SO4×n−factor
50 mL×0.1M×1=y mL×0.1M×2
∴y=25 ml
So, for complete reaction with 50 𝑚𝐿 𝑜𝑓 0.10 𝑀 𝑁𝑎𝑂𝐻, 25 𝑚𝐿 of 0.1 𝑀 H2SO4 is required.
Thus, the total volume of the solution after neutralization will be 50 𝑚𝐿 +25𝑚𝐿 = 75 𝑚L
To obtain 0.05 𝑀 H2SO4 , more volume of 0.10 𝑀 H2SO4 must be added.
Suppose the volume of 0.1 𝑀 H2SO4 to be added to this solution to make the molarity of sulphuric acid equal to 0.05 𝑀, is 𝑥 𝑚𝐿,
Then,
𝑉1 = Extra volume of H2SO4 needed = 𝑥 𝑚𝐿
𝑀1 = Molarity of H2SO4 = 0.10 𝑀
𝑉2 = Total volume of the resultant solution
after adding extra H2SO4 = (75 + 𝑥) 𝑚𝐿
𝑀2 = Molarity of the resultant solution
= 0.05 𝑀
We know that M1V1=M2V2
x×0.10M=(75+x)×0.05 M
0.10x=3.75+0.05x
0.05x=3.75
x=3.750.05=75 mL
Thus, the total volume of 0.10M H2SO4
required = 25 𝑚𝐿 (for neutralizing
50 𝑚𝐿 𝑜𝑓 0.10 𝑀 𝑁𝑎𝑂𝐻) + 75 𝑚𝐿 (for
attaining the 0.05 𝑀 concentration)
= 100 𝑚𝐿
So, option (C) is the correct answer