Answer:
Balanced reaction: 
S is oxidized and N is reduced.
is the oxidizing agent and ZnS is the reducing agent.
Explanation:
Reaction: 
Oxidation: 
Balance charge:
...............(1)
Reduction: 
Balance H and O in acidic medium : 
Balance charge:
...............(2)
[
Equation-(1)] + [
Equation-(2)]:

Oxidation number of S increases from (-2) to (0) for the conversion of ZnS to S. Therefore S is oxidized.
Oxidation number of N decreases from (+5) to (+2) for the conversion of
to NO. Therefore N is reduced.
consumes electron from ZnS. Therefore
is the oxidizing agent and ZnS is the reducing agent.
Answer:
The pH of the buffer solution = 8.05
Explanation:
Using the Henderson - Hasselbalch equation;
pH = pKa₂ + log ( [HPO₄²-]/[H₂PO4⁻]
where pKa₂ = -log (Ka₂) = -log ( 6.1 * 10⁻⁸) = 7.21
Concentration of OH⁻ added = 0.069 M (i.e. 0.069 mol/L)
[H₂PO4⁻] after addition of OH⁻ = 0.165 - 0.069 = 0.096 M
[HPO₄²-] after addition of OH⁻ = 0.594 + 0.069 = 0.663 M
Therefore,
pH = 7.21 + log (0.663 / 0.096)
pH = 7.21 + 0.84
pH = 8.05
Answer:
Cl-
Explanation:
Neutral (Cl) have 7 electron, but Cl- have 8 electron due to gain of 1 electron