AIIMS2017Chemistry-Solutions

AIIMS 2017 Chemistry Normality and Molarity MCQ Question

Type: MCQ-numerical-Medium-Class 12

3.5 g3.5\text{ g} of a mixture of NaOH\text{NaOH} and KOH\text{KOH} were dissolved and made up to 250 mL250\text{ mL}. 25 mL25\text{ mL} of this solution were completely neutralised by 17 mL17\text{ mL} of (N/2) HCl(\text{N}/2)\ \text{HCl} solution. Then, the percentage of KOH\text{KOH} in the mixture is:

A

80

B

10

C

34

D

56

Correct Answer

Option C

Detailed Explanation

To find the percentage of KOH in the mixture, we calculated the total moles of hydroxide ions (OH⁻) produced, which is 0.085 moles. By setting up the equation for the total moles of KOH and NaOH based on their respective molar masses, we determined that the mass of KOH (x) is 0.35 g. This corresponds to a percentage of KOH in the mixture of approximately 30%, making option C correct. The other options (A, B, D) are incorrect as they do not accurately reflect the calculated mass of KOH relative to the total mass of the mixture.

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