Can someone me figure this out? i'm lost.

First balance the equation with the following coefficients respectively: 2 2 1
This is solved by subtracting the summation of the stoichiometric coefficient of the products multiplied by the heat of formation and the summation of the stoichiometric coefficient of the reactant multiplied by the heat of formation of the certain specie. 

1(0)+2(0) - (2)(-90.83) = 181.66 or 182 J

I’d have to say no because without oxygen in the water the fish would all be dead. so if you want to fish for dead fish, pick the ponds with the lowest oxygen concentrations.

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na