Question

The number of milliequivalents of acid in 100 mL of 0.5N of HCl solution is:
A.50
B.100
C.25
D.200

Answer 1

Hint:Normality is described as the number of grams or mole equivalents of solute present in one liter of solution. It is the ratio of gram equivalents of the solute to the volume of the solution in liters.
Equivalent weight is the mass of the one equivalent that is equal to the mass of the given substance which will combine with or displace a fixed quantity of another substance.

Complete step by step answer:
The given normality of HCl is 0.5N and the volume is 100 mL.
Since 1 L is equal to 1000 mL, therefore 100 mL is equal to 0.1 L.
Let us assume that the number of gram equivalents of HCl is x, using all these values we have:
${{0}}{{.5N = }} {{{x}}}{{{{0}}{{.1L}}}}$
Which gives us, x \[ = \] 0.05 gram equivalents per liter.
We need the value of gram equivalent in milliequivalents, for that we need to multiply the quantity by 1000. Therefore, 0.05 gram equivalents are equal to 50 milliequivalents.

Hence, the correct answer is option A.

Note:
Normality is one of the methods used to measure the concentration of a solution. There are several other methods too. Some of the methods are:
Molarity: Molarity is the number of moles of solute per liter of the solution.
Molality: It is defined as the number of moles of solute per kilograms of the solvent.
Mole fraction: It represents the number of moles of a particular component of a mixture divided by the total number of moles of all the components of the given mixture.
Similarly, there are quite a few more. But these are the most important methods.