Question

Calculate normality of 20gm NaOH for 100 ml solution

Answer 1

Answer:

normality =5N

Explanation:

equivalent mass of NaOH=40g

equivalent moles of given NaOH=20/40

=0.5g mol equi.

Normality =gram mole solute/volume of solution in litre

=0.5/(100/1000) ----we divide it by 1000 to convert ml into litre

=0.5*10

=5N

Answer 2

Answer:

The normality of $20g$ $NaOH$ for $100 ml$ solution measured is $5N$.

Explanation:

Given,

The mass of $NaOH$ = $20g$

The volume of the solution = $100ml$

The normality of the solution, N =?

As we know,

• The normality can be calculated by the equation given below:
• Normality = $\frac{weight}{equivalent weight}\times \frac{1000}{V (ml)}$    -------equation (1)

Now, we have to find out the equivalent weight of $NaOH$.

As we know, the dissociation of $NaOH$ occurs in the way given below:

• $NaOH \rightarrow Na^{+} + OH^{-}$

• There is only $1 OH^{-}$, so the number of equivalents is 1.

Also, the molar mass of $NaOH$ = $40g/L$

Now,

• Equivalent weight = $\frac{Molar mass}{number of equivalents}$ = $\frac{40}{1}$ = $40g/L$

After putting the values in equation (1), we get:

• Normality = $\frac{20}{40}\times \frac{1000}{100}$ = $5N$

Hence, the normality of the solution = $5N$.