posted by Shawn on .
Nitric acid is produced commercially by the Ostwald
process, represented by the following equations:
4NH3(g) + 5O2(g) > 4NO(g) + 6H2O(g)
2NO(g) + O2(g) > 2NO2 (g)
3NO2(g) + H2O(l) > 2HNO3(aq) + NO(g)
What mass of NH3 must be used to produce 1.0x10^6 kg HNO3 by the Ostwald
process? Assume 100% yield in each reaction [and assume that the NO produced in the third step is not recycled.]
Convert 1.0 x 10^6 kg HNO3 to mols HNO3. I assume you know mols = grams/molar mass.
Then convert mols HNO3 to mols NO2 using the coefficients in the last equation (equation 3).
You must have omitted the third step since that was to be ignored.
Convert mols NO2 to mols NO using the coeffieicnts in the second equation.
Convert mols NO to mols NH3 using the coefficients in the first equation.
Finally, convert mols NH3 to grams NH3 remembering that grams = mols x molar mass.
Post your work if you get stuck.
HNO3 mols =15873015.87
which means 95238095.24 mols of NO2
Because the coefficient of NO2 and NO and NO and NH4 are the same, there are 95238095.24 NH4.
Multiply that by the molar mass (17) and divide by 1000 gets me 1619047.619 kg. Is this right?