Question

The maximum n-factor $\left(n_f\right)$ for $H_{3}P{O}_3$ and $H_{3}P{O}_4$ respectively is:

• A. $3,4$
• B. $2,3$
• C. $3,3$
• D. $3,2$

Answer 1

The correct option is B $2,3$

$n_f$ for acid is number of $H^{+}$ ions that can replaced per molecule of acid.
$H_{3}P{O}_3$ structure :


In the above structure we can see that there are two $O-H$ bonds . Both $H^{+}$ can be replaced.

$n_f$ for $H_{3}P{O}_3$ is $2$

$H_{3}P{O}_4$ structure:



n the above structure we can see that there are three $O-H$ bonds . All three $H^{+}$ can be replaced.

$n_f$ for $H_{3}P{O}_4$ is $3$