Answer:
D
Explanation:
A weak acid and a strong base will form a basic salt.
Option A is acidic, this pH would be found in salts formed from reactions between strong acids and weak bases.
B and C are neutral or close to neutral and as such will be formed from weak acids and weak bases, or strong acids and strong bases.
Answer:
Coefficient of
is more than 4
Explanation:
Oxidation: 
- Balance charge:
......(1)
Reduction: 
- Balance Cr:

- Balance O and H in acidic medium:

- Balance charge:
.......(2)
gives balanced equation:

So coefficient of
is more than 4
I’m not to sure but let me figure it out hold up