A gaseous reaction takes place in a rigid 2.00 L vessel at constant temperature: 2…
CHEMISTRY · Multi-part · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
A gaseous reaction takes place in a rigid 2.00 L vessel at constant temperature:
2 X(g) ⇌ Y(g)
The vessel initially contains only X(g) at a concentration of 0.800 M. During the experiment the concentrations of X and Y are monitored. The investigator summarizes the key features of the concentration–versus–time curves as follows.
• [X] decreases steadily from 0.800 M to a constant value of 0.350 M.
• [Y] rises from 0 M to a constant value of 0.225 M.
No other species are present.
Answer the following questions about the system.
(a) Demonstrate, using numerical evidence from the plateau values, that the experimental data are consistent with the balanced chemical equation provided.
(b) Calculate the fraction of the original X(g) that has been converted to product at equilibrium.
(c) Determine the ratio [X]_eq/[Y]_eq and explain what this reveals about the relative abundances of reactant and product in the equilibrium mixture.
(d) If the total pressure in the vessel at equilibrium is measured to be 1.35 atm, determine the partial pressure of each species in the vessel at equilibrium.