Equation Stoichiometry with Gases at the Same Temperature and
Nitric acid, which is
used in the manufacture of fertilizers and explosives, can be made from
ammonia, NH3, and oxygen, O2. The three-step
process is summarized in the following net reaction:
NH3(g) + 2O2(g)
HNO3(l) + H2O(l)
What is the minimum
volume of oxygen gas at 22.4 C and 271 kPa that would react completely
with 875 L NH3 at the same temperature and pressure?
The dimensional analysis sequences laid out below show the
use of two different values of R as conversion factor. Notice that all of the
numbers cancel except the coefficients from the balanced equation.
Shortcut: Because the gases are at the same temperature and
pressure, the molar ratio constructed from the coefficients in the balanced
equation is equal to the volume ratio of the gases expressed in liters.
Therefore, it is the only factor necessary to convert the volume of one gas into
the stoichiometrically equivalent volume of the other.
here to see an exercise that will allow you to try this task yourself.
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