Question

Assertion : $H_{3}P{O}_3$ is a dibasic acid and its salt $N{a}_{3}P{O}_3$ does not exist.

Reason : Being dibasic in nature means only two $H$ are replacable.

• A. Both Assertion and Reason are correct and Reason is correct explanation of Assertion.
  
• B. Both Assertion and Reason are correct but Reason is not correct explanation of Assertion.
  
• C. Assertion is correct but Reason is incorrect.
  
• D. Assertion is incorrect but Reason is correct.
  

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is correct explanation of Assertion.

One molecule of $H_{3}P{O}_3$ can react with two molecules of a base. Hence, it is a dibasic acid.

In $H_{3}P{O}_3$, two $H$ atoms are attached to $O$ atoms and one $H$ atom is attached to $P$ atom. Hence, only two $H$ atoms can be replaced with two sodium atoms to form $N{a}_{2}HP{O}_3$ .

Thus, $N{a}_{3}P{O}_3$ is not possible.