Since water is already at 100<span>°C all the energy is used to evaporate it.
Now we can calculate how many </span>mols of water are evaporated with 820kJ.

We calculated that we got 20 mols of water evaporated. Now, all we have to do is find how many grams is a mol of water. Molar mass of water is <span>20.16 g/mol.
</span>The final answer is:
Answer:
the answer is 70.906 g/mol
Explanation:
1) The forward reaction is N2 (g) + O2 (g) → 2NO
(that reaction requires special contitions because at normal pressures and temperatures N2 and O2 do not react to form another compound.
2) The equiblibrium equation is
N2 (g) + O2 (g) ⇄ 2NO
3) Then, the reverse reaction is
2NO → N2(g) + O2(g)
Answer: 2NO → N2(g) + O2(g)