Question

Question 1. In the following reaction calculate and find the normality when it is 1.0 M H3PO4

H3AsO4 + 2NaOH → Na2HAsO4 + 2H2O

​

Answer 1

Answer: 2

Given:

$\sf Molarity(M)=1.0\:M$

To find:

$\sf Normality(N)$

Formula used:

$\boxed{\sf{Normality (N)= Molarity(M)}\times Number\ of\ equivalents}$

Explanation:

$\sf\textbf{``Normality is the number of gram equivalents per litre solution''}$

$\sf\text{According to the question,}$

$\sf H_3AsO4+2NaOH{\longrightarrow}Na_2HAsO4+2H_2O$

$\sf\text{Here, only two out of three of}\ H^+ \sf\text{ions reacts with NaOH to form the product.}$

$\sf\text{Therefore, the number of equivalents is}\: 2$

$\sf\text{Substituting all the values in the formula, we get:}$

$\sf N=1.0\times2$

$\sf Normality(N) = 2$

$\sf\textbf{Hence, the normality of the solution is 2.}$