Question

Nitric Acid is produced from nitric oxide, NO which in turn is prepared from ammonia by the ostwald process.

4NH3 + 5O2 -----> 4NO + 6H2O

What volume of oxygen at 35 degrees C and 2.15 atm is neeeded to produce 50.0 g of nitric oxide

T= 273+35 = 308 K
P = 2.15 atm
n= 50.0 g ( 1 mol/ 30 g)= 1.667 mol
R= 0.0821
V= ?

2.15 (V) = 1.67(.0821)(308)

ANSWER:
V= 19.64

Is this correct

Answer 1

Your answer would be correct if you had used the correct number for n, the number of mols.
mols NO = 30/50 = 1.67
Now convert mols NO to mols O2 using the coefficients in the balanced chemical equation.
mols O2 = 1.67 mols NO x (5 mols O2/4 mols NO) = 2.08 mols O2.
Substitute 2.08 for mols O2 and you will have the correct answer.