Acidic, Neutral, or Basic Salts?

Identify the following salts as acidic, neutral, or basic:

NH4Br
KCN
NH4CN
SrBr2
NH4ClO4
LiF
LiNO3

and how do you know which are acidic, neutral, and basic?

Answer:
Conjugated acids and bases of strong bases and acids, respectively, are weak acids and bases. In easier words, the conjugate acid of a strong base is a weak acid and the conjugated base of a strong acid is a weak base. On the other head, the conjugated acid of a weak base is a stronger acid and same holds true for a weak acid. Acidity, neutrality, and basicity are measured in the pH scale, which is the negative log of the concentration of [H+] within the solutions. Acidity implies that the pH is between 0 and 7, neutral is at 7, and finally, basicity means that the pH is between 7 and 14. In order to determine whether salts are acidic, neutral, or basic, you'd have to look at the solution they form when they are desolved in water.

1. NH4Br --> NH4 + Br -
a. since Br - is the conjugate base for HBr (strong acid), therefore it is a weak base and it doesnt alter the pH of the solution.
b. NH4 is the conjugate acid of NH3 (weak base) therefore it is a stronger acid, so it decreases the pH of the solution.
c. NH4Br is an acidic salt

2. KCN
a. K+ is conjugate acid of KOH (strong base --> weak conjugate acid --> no effect on the pH
b. CN- is conjugate base of HCN (weak acid --> strong conjugate base --> increases pH)
c. KCH is a basic salt

3. NH4CN
a. NH4+ is conjugate acid of HN3 (weak base --> strong conjugate acid --> decrease pH)
b. CN- is conjugate base of HCN (weak acid --> strong conjugate base --> increases pH)
c. since you cant qualitatively decide which has a stronger effect, you have to look up the pKa values of these ions. The one with a larger pKa value takes the more effect.

following these rules...you should be able to figure out the rest...
4. neutral
5. acidic
6. basic
7. neutral
These are identified with their pH values.
If the pH value is less than 7 then it is called acidic nature. If the pH value is greater than 7 it is called basic. And if the pH value is equal to 7 then it is called neutral.(water has pH value 7 and is the neutral solution)
i am refererring to the solutions of the said salts

NH4Br =acidic (HBr is a strong acid)
KCN = basic (KOH is a strong base)
NH4CN = neutral (NH4OH and HCN is weak acid and base)
SrBr2 = acidic (HBr is a strong acid)
NH4ClO4 = neutral
LiF = basic (LiOH is strong base)
LiNO3 = basic (HNO3 is a strong base)


that is only based on Ka values of acids and bases formed from salts above, that is if my memory is correct.
1.a
2.b
3.a
4.n
5.a
6.a
7.a

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