What happens if q k

The value of K c at K is As a result, some of the reactants will become products, causing the reaction to shift to the right. To decrease the amount of products, the reaction will shift to the left and produce more reactants. Remembering these simple relationships will aid you to solving for the progression of a reaction. A chart outlining them can be found below. Depending on what a problem asks of you, sometimes it is unnecessary to make any calculations at all.

Take, for example, the now familiar reversible reaction listed below :. What do you think will happen if more of the product, methanol CH3OH , is added? In order to re-establish equilibrium, the reaction will progress to the left, towards the reactants.

This means some of the added methanol will break down into carbon monoxide and hydrogen gas. The reaction quotient can be used to determine whether a reaction under specified conditions will proceed spontaneously in the forward direction or in the reverse direction. Three properties can be derived from this definition of the reaction quotient:.

Eventually, the concentrations become constant; at this point, the reaction is at equilibrium. The equilibrium constant, K eq , can be expressed as follows:. This expression shows that Q will eventually become equal to K eq , given an infinite amount of time. However, most reactions will generally reach equilibrium in a finite period of time. Like in example 5I. Since we want the reaction to proceed to equilibrium, we want to create more product so that the ratio of products to reactants increases from Q to K, so the forward reaction is favored in order to generate more product in order to reach the desired K value.

Lavelle said that there may be some other source adding reactant than products being removed, so in order to decrease the amount of reactant to reach equilibrium, the forward reaction is favored to produce more product. Because there are more reactants than products, so in order to reach K the reaction will proceed forward. The activity is defined as a dimensionless quantity and is equated to the concentration variable multiplied by an activity coefficient f or g.

Most concentration variables have mathematical dimensions, so the activity coefficient must have dimensions which cancel out those of the concentration. The concentration units to be used for activity depend on the physical state of the component, so the reaction that we are considering must include these physical states:.

For a gas , the activity may be written in terms of the partial pressure in atmospheres or bars, or in terms of molarity :.

For a pure liquid or a pure solid , the concentration variable is " 1 ", provided that some of the material is present otherwise it's activity is zero :. There are cases in which a component such as water H 2 O may play the role of solvent as well as that of a reacting component. The physical state is shown as l , but a solvent cannot be a pure liquid. In this case, the concentration variable is the mole fraction X B :.

Activities and activity coefficients have been designed so that activity coefficients may be approximated as " 1 " for many of the situations of interest to Chemists. These situations are called "ideal" as in " ideal gas ", " ideal solution ", or " ideal dilute solution ":.

Writing the Reaction Quotient:.