Keq = [P]/[R]
Why are they using the amounts of reactants left over in the equation?
Thanks!
I have another related question.
Say that the system was not at equilibrium, then we calculate Q using a similar formula, Q = [P]/[R]. So if we are asked to calculate Q, they would have to tell us how much of the reactants have reacted by that given point in time so we can determine the ratio of [P]/[R] present at that given point. This would also mean that Q would change with time in the reaction, increasing as we reach equilibrium. Am I correct?
Say that the system was not at equilibrium, then we calculate Q using a similar formula, Q = [P]/[R]. So if we are asked to calculate Q, they would have to tell us how much of the reactants have reacted by that given point in time so we can determine the ratio of [P]/[R] present at that given point. This would also mean that Q would change with time in the reaction, increasing as we reach equilibrium. Am I correct?
Fantastic! In general this Q highlights the cleverness of the MCAT. The Keq is always a ratio of products to reactants, which must always involve ANY products or reactants than can be expressed as concentration (i.e. no solids or liquids). The subtlety of having you determine the reactant concentrations as amount left rather than just giving them to you illustrates how the MCAT rewards critical thinking WAY MORE than plugging and chugging.Holy **** you guys this thread was crazy helpful. As a token of my gratitude I offer you this meme...
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