Partial neutralization of a polybasic acid can result in the formation of various types of salts depending on the number of acidic hydrogen atoms neutralized. The type of salt formed can be categorized as acidic salt, basic salt, normal salt, or double salt.

1. Acidic Salt:
When only one or some of the acidic hydrogen atoms of a polybasic acid are neutralized, an acidic salt is formed. In an acidic salt, the remaining acidic hydrogen atoms are still present in the salt, which makes it acidic in nature. These salts typically have a pH less than 7. For example:

- Sodium dihydrogen phosphate (NaH2PO4): In this salt, only one of the two hydrogen atoms of phosphoric acid (H3PO4) is neutralized, resulting in an acidic salt.

2. Basic Salt:
If all the acidic hydrogen atoms of a polybasic acid are neutralized, a basic salt is formed. In a basic salt, all the acidic hydrogen atoms are replaced by metal cations, resulting in a pH greater than 7. These salts can act as bases and can undergo hydrolysis to produce a basic solution. For example:

- Calcium carbonate (CaCO3): When all three acidic hydrogen atoms of carbonic acid (H2CO3) are neutralized, calcium carbonate is formed.

3. Normal Salt:
A normal salt is formed when all the acidic hydrogen atoms of a polybasic acid are completely neutralized by metal or ammonium cations. In a normal salt, the acidic nature of the acid is completely eliminated, resulting in a neutral pH of 7. For example:

- Sodium chloride (NaCl): When all the acidic hydrogen atoms of hydrochloric acid (HCl) are neutralized, sodium chloride is formed.

4. Double Salt:
A double salt is formed when two different salts are combined in a definite ratio and crystallize together to form a single compound. The constituent salts retain their individual properties and can be separated by physical means. For example:

- Potassium alum (KAl(SO4)2.12H2O): It is a double salt formed by the combination of potassium sulfate (K2SO4) and aluminum sulfate (Al2(SO4)3).

In summary, the type of salt formed during partial neutralization of a polybasic acid depends on the number of acidic hydrogen atoms neutralized. If only some of the hydrogen atoms are neutralized, an acidic salt is formed. If all the hydrogen atoms are neutralized, a basic salt is formed. When all the acidic hydrogen atoms are completely neutralized, a normal salt is formed. Double salts are formed when two different salts combine in a definite ratio.

sImplE dude its (a) acidic salt