The number of moles of water vapor formed in the reaction is 0.158 moles
The ideal gas equation shows the relationship between number of moles, temperature, volume and pressure.
Now;
P = 122.3 kilopascals or 1.21 atm
V = 5.4 L
T = 730°c or 1003 K
n = ?
R = 0.082 atmLK-1mol-1
PV = nRT
n = PV/RT
n = 1.21 * 5.4/0.082 * 1003
n = 6.53/82.2
n = 0.079 moles
The equation of the reaction is; O2 (g) + 2H2(g) ---->2H2O(g)
If 1 mole of O2 formed 2 moles of H2O
0.079 moles of O2 yield x moles of H2O
x = 0.079 * 2/1
= 0.158 moles
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