[Tymed]

Just got my equilibrium quiz back and there's two questions that I got wrong which make no sense why I got them wrong...

Q1: Methanol can be produced by this equilibrium. The conditions that are necessary to maximize the equilibrium yield of methanol are:

CO _(g) + 2H_{2 (G)}  CH₃OH _(G) + ENERGY

a. low temp and high pressure
b. high temp and low pressure
c. low temp and low pressure
d. high temp and high pressure

the answer is A, why?.
and ...

Q2; A chemical equilibrium is described as dynamic because

a. the pressure and temp do not change
b. the concentrations of chemical species remain constant
c. maximum randomness has been achieved
d. both reactants and products continue to form

the answer is apparently D, why?. -___-"

[UG]

Have you heard of Le Chatelier's principle? The first question is an application of this principle. If the reaction was written:
CO (g) + 2H₂ (g) CH₃OH (g) + HEAT ENERGY
would that make you think any differently? A decrease in the temperature would favour the reaction which produces an increase in temperature/more heat energy. All of the reactants and products are gases, when you increase the pressure on a system, the reaction which produces the least number of gaseous molecules is favoured, so again the reaction producing methanol is favoured. These things are all stated in Le Chatelier's principle. For question two, a chemical equilibrium is dynamic because both product and reactants continues to form. This is true because equilibrium is not static, just because you cannot see anything happening with your eyes doesn't mean that nothing is happening. For a general reaction like A(g) B(g), equilibrium is reached when the rate of formation of A is the same as the rate of formation of B. A is constantly forming B and B is constantly forming A, these two occur at the same rate so their net effect is no reaction, this is why equilibrium is dynamic.