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

Hint: 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.