A stoichiometric mixture of gaseous nitrogen and hydrogen is prepared for the…
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A stoichiometric mixture of gaseous nitrogen and hydrogen is prepared for the industrial synthesis of ammonia.
At 450 ∘C and 3.00 atm, a chemist introduces 2.00 L of N2 into a reaction vessel already containing an equal-temperature, equal-pressure sample of H2. No reaction is allowed to occur.
Answer the following without performing detailed numerical calculations.
(a) Write the balanced chemical equation for the formation of gaseous ammonia from its elements.
(b) At the stated temperature and pressure, determine the volume of H2 that must be present in the vessel so that the two gases are present in exactly stoichiometric proportions. Explain your reasoning with reference to the microscopic interpretation of a balanced equation.
(c) The chemist now doubles the external pressure on the vessel while holding the temperature constant (no reaction yet occurs). Explain qualitatively whether the volume ratio you identified in part (b) would change, and justify your answer in terms of the quantities that remain constant and those that do not.
(d) Describe, in words, how the conservation of atoms is reflected in the numerical coefficients of the balanced equation from part (a) and in the volume relationship discussed in parts (b) and (c).