A) 2H₂(g) + O₂(g) → 2H₂O(l) + 285.83 kJ
Exothermic
B) 2Mg + O₂ → 2MgO + 1200kJ
Exothermic
Answer : The moles of
formed are, 22.3 moles.
Explanation : Given,
Moles of
= 16.72 mol
The given chemical reaction is:

From the balanced chemical reaction, we conclude that:
As, 3 moles of
react to give 4 moles of 
So, 16.72 moles of
react to give
moles of 
Therefore, the moles of
formed are, 22.3 moles.
Answer:
80.7 L
Explanation:
PV = nRT
P = 1520 mmHg = 2 atm
n = 5 mol
R = 0.08206 (L * atm)/(mol * K)
T = 393.15 K
2 (V) = 5 (0.08206) (393.15)
V ≈ 80.7 L