3H2 + N2----≥ NH3. All of the following will lead in this reaction to the production of more NH3 except? Correct answer is a decrease in the volume of the container, but by decreasing volume pressure increase(Boyle's law) so reaction should proceed in f

1 Answer
Jul 1, 2018

Wild Guess: There are changes in factors other than pressure and volume (esp. temperature) during the compression.


Reducing the volume of the container through compression does work on the gas, thereby increasing its temperature.

The forward reaction is exothermic (#Delta H = -46 color(white)(l) "kJ" * mol^(-1)#) and is favored at low temperatures. Increasing the temperature shifts the equilibrium position to the left. The impact on the equilibrium of the system due to the change in temperature might overwhelm that due to the increase in pressure.

This observation might be especially remarkable if the gas is compressed rapidly rather than gradually in a way that allows the temperature of the system to return to its initial level.