Question

What do you mean by decinormal solution?

Answer 1

Normality:

• It is the measure of concentration equal to the gram-equivalent mass of a substance per liter of solution.

Decinormal solution:

• A decinormal solution is described as one-tenth of the normal solution.
• A solution containing one-tenth $\left(\frac{1}{{10}^{\mathrm{th}}}\right)$ gram equivalent mass of a substance, present in one liter of its solution is called a decinormal solution.
• It is represented as $\left(\frac{\mathrm{N}}{10}\right)$ or $0.1\mathrm{N}$.

For example, for $0.1\mathrm{N}$ solution of $\mathrm{HCl}$ in $250\mathrm{ml}$ flask. the calculations will be as follows:

$$\begin{gathered} \mathrm{Normality}=\frac{\mathrm{gram}\mathrm{equivalent}}{\mathrm{Volume}} \\ 0.1\mathrm{N}=\frac{\mathrm{x}}{2.5\mathrm{L}} \\ \mathrm{x}=0.1\times 2.5=0.25\mathrm{g}{\mathrm{eq}}^{-1} \end{gathered}$$

For $\mathrm{HCl}$, gram equivalents= Number of moles

Thus, 0.25 moles of $\mathrm{HCl}$ is $250\mathrm{ml}$ of water is required to make $0.1\mathrm{N}$ solution of $\mathrm{HCl}$.