Respuesta :
The given question is incomplete, the complete question is:
Calculating an equilibrium constant from a partial equilibrium... Steam reforming of methane (CH) produces "synthesis gas," a mixture of carbon monoxide gas and hydrogen gas, which is the starting point for many important industrial chemical syntheses. An industrial chemist studying this reaction fills a 25.0L tank with 8.0 mol of methane gas and 1.9 mol of water vapor, and when the mixture has come to equilibrium measures the amount of carbon monoxide gas to be 1.5 mol. Calculate the concentration equilibrium constant for the steam reforming of methane at the final temperature of the mixture. Round your answer to 2 significant digits.
Answer:
The correct answer is 2.47.
Explanation:
Based on the given information, the equation for the synthesis gas is, Â
CH₄ (g) + H₂O (g) ⇔ CO (g) + 3H₂ (g)
Based on the given information, 25.0 L is the volume of the tank, the concentration of CHâ‚„ is 8.0 mol, the concentration of water vapor is 1.9 mol, and the concentration of CO gas is 1.5 mol. Â
Therefore, 25 L of the solution comprise 8.0 mole of CHâ‚„. So, 1 L of the solution will comprise 8.0 / 25 mole CHâ‚„, Â
= 0.32 mole of CHâ‚„
Thus, the concentration of CHâ‚„ or [CHâ‚„] will be 0.32 mole/L or 0.32 M. Â
Similarly, the concentration of Hâ‚‚O or [Hâ‚‚O] will be 1.9/25 = 0.076 M
and [CO] is 1.5/25 = 0.06 M
The concentration equilibrium constant for the steam will be, Â
Kc = [CO] pHâ‚‚ / [CHâ‚„] [Hâ‚‚O] (Here pHâ‚‚ is the partial pressure of Hâ‚‚)
Now lets us assume that the reaction has taken place in a constant atmospheric pressure, therefore, pHâ‚‚ will be equal to 1. Â
= 0.06 M/0.32 M × 0.076 M Â
= 2.47 Â