Free response · Unit 7 Beta

Justifying shifts in methanol synthesis

Short free response · 4 points

The question

Name: ______________________   Date: ____________   Justifying shifts in methanol synthesis (4 points)

Experimental setup

Making methanol from CO and H₂

Methanol is made by the reaction CO(g) + 2 H2(g) ⇌ CH3OH(g), ΔH° = −91 kJ/molrxn. At 500 K, Kp = 2.5 × 10−3. A reactor at 500 K contains CO at 2.0 atm, H2 at 4.0 atm and CH3OH at 0.20 atm.

  1. (a) Calculate Qp for the mixture in the reactor. [1 point]

  2. (b) Determine whether the partial pressure of CH3OH will increase, decrease or stay the same as the mixture approaches equilibrium. Justify your answer. [1 point]

  3. (c) Once the reactor is at equilibrium, its volume is decreased at constant temperature. Explain, in terms of Q and K, why the amount of CH3OH increases. [1 point]

  4. (d) The temperature of the equilibrium mixture is raised to 550 K. Predict whether Kp at 550 K is greater than, less than or equal to 2.5 × 10−3, and justify your prediction. [1 point]