Question

Calculate the amount of KOH required to neutralize 15 milliequivalents of HCL.
(A)-0.84g
(B)-0.80g
(C)-0.90g
(D)-None of the above

Answer 1

Equivalent weight of a substance is that weight which when reacts with 1 g of H. The formula to calculate the required weight of a substance is:
Weight in g = Equivalent weight $\times$ Normality

Complete step by step solution:
Let’s see what the solution will be:

The reaction for KOH and HCl is as follows
$KOH+HCl\to KCl+{{H}_{2}}O$
As we know that 1 equivalent of a base neutralizes 1 equivalent of an acid.
So, 15 milli equivalents of KOH will be required to neutralize 15 milli equivalents of HCl.
Now, the formula to calculate amount required in grams is:
Weight in g = equivalent weight $\times$ molar mass
Now, 1 milli equivalent $={{10}^{-3}}\times$equivalents
Therefore, 15 milli equivalent $=15\times {{10}^{-3}}$ equivalents
We know that equivalent weight of KOH $=56.1g$
Amount of KOH required $=56.1\times 15\times {{10}^{-3}}$
Hence, the amount of KOH required to neutralize 15 milli equivalents of HCl $=0.8415g$
Since the value in option (A) is close to the answer.

So, option (A) is the correct answer.

Additional Information:
Normality: It is defined as the ratio of molar mass to the acidity of the base for a base.

Note: The equivalent weight of monoacid bases are equal to their molar masses. KOH is a monoacidic base which means it gives only 1 hydroxyl ion in the solution.