<u>Answer:</u> The correct option is D) 
<u>Explanation:</u>
The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when oxidation number of a species increases.
A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when oxidation number of a species decreases.
For the given chemical reaction:

<u>On the reactant side:</u>
Oxidation number of Zn = 0
Oxidation number of Ag = +1
<u>On the product side:</u>
Oxidation number of Zn = +2
Oxidation number of Ag = 0
As the oxidation number of Ag is decreasing from +1 to 0. Thus,
is getting reduced.
Hence, the correct option is D) 
Answer:
The molar average velocity is 0.0588 cm/s
The N₂ diffusion velocity relative to the mole average velocity is -0.1428 cm/s
The molar diffusional flux of N₂ is -3.9x10⁻³
Explanation:
Given data:
T = temperature = 265 K
O₂ = 25%
N₂ = 60%
CO₂ = 15%
vO₂ = -0.084 cm/s
vN₂ = 0.12 cm/s
vCO₂ = 0.052 cm/s
The molar average velocity is equal:

The N₂ diffusion velocity relative to the molar average velocity is:

The molar diffusional flux of N₂ is:

https://sciencing.com/make-3d-model-atom-5887341.html
amount of product formed or amount of reactants used / time