Question

Which of the following is a normal salt?
A. $Na{H_2}P{O_2}$
B. $Na{H_2}P{O_3}$
C. $Na{H_2}P{O_4}$
D. $N{a_3}P{O_4}$

Answer 1

Hint: As normal salt is a salt formed by the complete replacement of replaceable hydrogen atoms from an acid. There are many types of salts so try to differentiate between them.

Step by step answer: So first of all we should know what salt is, and what its types are,
Definition of Salt: Salt is an ionic compound that results from the neutralization reaction of an acid and a base. It is composed of related numbers of cations (positively charged ions) and anions (negative ions) so that the product is electrically neutral (without a net charge).
Types of Salt:
Normal Salt: A normal salt is a salt which is formed by the complete replacement of replaceable hydrogen atoms from an acid molecule by means of a metal or a group of elements acting like a metal.
-Acidic Salt: An acid salt is one which contains one or more replaceable hydrogen atoms in its molecule and is formed by partial replacement of ${H^ - }$ atoms present in an acid molecule by means of metal or positive radical.
-Basic Salt: A salt which contains ${O^{2 - }}$ or $O{H^ - }$ group in its molecule is called basic salt.
-Alkaline Salt: Normal salts which are formed by the neutralization of weak acids and strong bases are called alkaline salts because their aqueous solutions turn red litmus blue.
-Neutral Salt: They are formed by the neutralization of strong acids and strong bases, are called neutral salts because their aqueous solutions are neutral to litmus.
So according to the definition, $Na{H_2}P{O_2}$is not a normal salt as it is an acidic salt.
Similarly $Na{H_2}P{O_3}$ is also acidic salt, so it is not a normal salt.
Now also $Na{H_2}P{O_4}$is also acidic salt, so it is also a rejected option.
As normal salt is a salt formed by the complete replacement of replaceable hydrogen atoms from an acid so $N{a_3}P{O_4}$is a normal salt.

So the correct option is D.

Note: The other three salts present in the options are examples of acidic salts. Salt is useful in our daily life in many ways for example in cooking, or as preservatives, or for melting salt and many more. Unless one is not totally aware of the definition of different types of salts it is tough to identify.