At any time, the reaction proceeds in both direction - even not during equilibrium.
In an equilibrium that is biased towards product - for example, a strong acid/base reaction, the product concentration could be higher than that of the substrate.
In an equilibrium that is biased towards substrate - for example, a weak acid/base reaction, the product concentration could be lower than that of the substrate, and the substrate will simply never used up.
The only correct answer is "There is no net change in the concentration of the reactants".
A reaction is spontaneous if the product has lower free energy than the substate, a law in thermodynamics.
Both graph depict a spontaneous reaction.
If all other conditions are equal, the reaction in graph B is likely to proceed more rapidly than the reaction in graph A.
This is because graph B has a more stable transition state, a lower activation energy barrier to overcome.
Catalysts decreases the free energy of the transition state in order to reduce the activation energy of the reaction.
Basically make the graph A becomes graph B above.
An enzyme increases the rate of a reaction by stabilizing the transition state.
No comments:
Post a Comment