- #1
skepticwulf
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Homework Statement
Ammonia reacts with O2 to form either NO(g) or NO2(g) according to these unbalanced equations:
NH3 + O2 ----> NO + H2O
NH3 + O2 ----> NO2 + H2O
In a certain experiment 2.00 moles of NH3 and 10.00 moles
of O2 are contained in a closed flask. After the reaction is
complete, 6.75 moles of O2 remains. Calculate the number
of moles of NO in the product mixture: (Hint: You cannot
do this problem by adding the balanced equations because you
cannot assume that the two reactions will occur with equal
probability.)
Homework Equations
The Attempt at a Solution
After the balance of equations,
x=mol of NH3 in the first equations(=mol of NO as well)
1st reaction:
2 mol NH3 gives 5/2 mole O2
x mol gives ... 5x/4 mole O2
2nd reaction:
2 mol NH3 gives 7/2 mole O2
(2-x) mol gives ... 7(2-x)/4 mole O2
5x/4 + 7(2-x)/4 + 6.75=10
I find: x=0.5 mole of NH3 as well as 0.5 mole of NO
But solution manual has 0.48 as answer, is my calculation wrong in any way??