Methanol, CH3OH, is produced on an industrial scale from carbon monoxide and hydrogen. At the temperatures used, gaseous methanol is formed according to the following thermochemical equation:
CO(g)+ 2H2(g) <---> CH3OH(g) H = -90Kj
1. State Le Chateliers principle and explain the following:
a)The effect that increasing the pressure will have on the equalibrium yield of menthanol
b) the effect of increasing the temperature will have on the equalibrium yield of menthanol
c) the effect of increasing the temperature will have on the rate of reaction
where appropriate, show clear understanding of how the Le Chatelier's principle applies
It would benefit you if I were to critique your thinking. Notice the reaction is exothermic, more volumes of gas are on the left side.
Le Chatelier's Principle States that
"IF a stress is applied to a system at equilibrium,the system acts in such a way so as to nullify,as far as possible,the effect of that stress"
a) According to Le Chatelier's principle, when the pressure is increased, the equilibrium will shift in the direction that reduces the total number of gas molecules. In this case, there are a total of 3 moles of gas on the reactant side (1 mole of CO + 2 moles of H2) and only 1 mole of gas on the product side (1 mole of CH3OH). Therefore, increasing the pressure will favor the reaction that produces fewer moles of gas. As a result, the equilibrium yield of methanol will increase.
b) Increasing the temperature will favor the endothermic reaction in order to absorb the excess heat. According to Le Chatelier's principle, when the temperature is increased, the equilibrium will shift in the direction that absorbs heat. In this case, the forward reaction is exothermic, meaning it releases heat (-90 kJ). If the temperature is increased, the equilibrium will shift to the left, reducing the yield of methanol. This is because the reverse reaction is endothermic and absorbs heat.
c) Increasing the temperature will generally increase the rate of reaction. As mentioned earlier, the forward reaction is exothermic. According to the Arrhenius equation, an increase in temperature increases the rate constant of a reaction, resulting in a faster rate of reaction. However, it's important to note that the rate of reaction is not solely determined by temperature and may also depend on other factors such as concentration or catalysts. Therefore, increasing the temperature will have a positive effect on the rate of reaction, but it may not be the sole determining factor.