Answer is D.
Among the given options, the products of equation A, B and C are aqueous solutions. Those are indicated by using (aq).
The balanced equation for the reaction between Li₂CO₃(aq) and FeCl₂(aq) is Li₂CO₃(aq) + FeCl₂(aq) → 2LiCl(aq) + FeCO₃(s)
LiCl is a salt while FeCO₃ is a Grey/green color precipitate. Hence, option D represents a precipitation reaction.
Answer:
Atoms
Explanation:
This is also a form of molucules
A combustion reaction usually happens when a hydrocarbon is reacted with an oxygen molecule producing water and carbon dioxide. It is an exothermic reaction which means it releases heat as the process proceeds. It is a spontaneous process where it readily happens without any supply of energy. The total kinetic energy of the reactants is greater than the activation energy that is why heat is being released. Acetic acid is a carboxylic acid and is classified as a hydrocarbon so when reacted with oxygen, it would yield carbon dioxide and water. The balanced chemical reaction would be as follows
CH3COOH + 2 O2 = 2 CO2 +2 H2O
Explanation:
For what I can see, is missing the concentration of [Ag+] in the half-cell. To calculate it:
Niquel half-cell
Oxidation reaction: 
![E=E^0 - \frac{R*T}{n*F}*ln(1/[Ni^{2+}])](https://tex.z-dn.net/?f=E%3DE%5E0%20-%20%5Cfrac%7BR%2AT%7D%7Bn%2AF%7D%2Aln%281%2F%5BNi%5E%7B2%2B%7D%5D%29)
Assuming T=298 K / R=8.314 J/mol K / F=96500 C
Silver half-cell
Reduction reaction: 
![E=E^0 - \frac{R*T}{n*F}*ln(1/[Ag+])](https://tex.z-dn.net/?f=E%3DE%5E0%20-%20%5Cfrac%7BR%2AT%7D%7Bn%2AF%7D%2Aln%281%2F%5BAg%2B%5D%29)
Assuming T=298 K / R=8.314 J/mol K / F=96500 C
![0.835V=0.8V - \frac{8.314*298}{1*96500}*ln(1/[Ag+])](https://tex.z-dn.net/?f=0.835V%3D0.8V%20-%20%5Cfrac%7B8.314%2A298%7D%7B1%2A96500%7D%2Aln%281%2F%5BAg%2B%5D%29)
![[Ag+]=0.26 M](https://tex.z-dn.net/?f=%5BAg%2B%5D%3D0.26%20M)
