Question

Why does phosphorous acid form only two series of salts, even though the molecule contains three hydrogen atoms?

a) The third hydrogen atom is in a different oxidation state and does not form salts.

b) The third hydrogen atom is weakly acidic and does not participate in salt formation.

c) Phosphorous acid undergoes decomposition before forming a third series of salts.

d) The third hydrogen atom forms an unstable salt that quickly decomposes.

Answer 1

Phosphorous acid forms only two series of salts because the third hydrogen atom is weakly acidic and does not participate in salt formation.

Step-by-step explanation:

Phosphorous acid, H3PO3, forms only two series of salts because the third hydrogen atom is weakly acidic and does not participate in salt formation. The molecule contains three hydrogen atoms, but only the two hydrogen atoms bonded to an oxygen atom are acidic. The bond between phosphorus and the third hydrogen atom is not very acidic and does not easily ionize to form salts.