Consider the following system at equilibrium: P(aq)+Q(aq)⇌3R(aq)
1. Classify each of the following actions by whether it causes a leftward shift, a rightward shift, or no shift in the direction of the net reaction. Drag the appropriate items to their respective bins.
1) Increase(P)
2) Increase(q)
3) Increase (R)
4) Decrease (P)
5) Decrease(q)
6) Decrease (R)
7) Triple (P) and reduce (q) to one third
8) Triple both (Q) and (R)
A. Leftward Shift
B. Rightward Shift
C. No Shift
2.The following system is at equilibrium:
3M(g)+N(s)⇌2L(g)
Classify each of the following actions by whether it causes a leftward shift, a rightward shift, or no shift in the direction of the net reaction. Drag the appropriate items to their respective bins.
1) Add more N
2) Remove some N
3) Increase the volume
4) Decrease the volume
A. Leftward Shift
B. Rightward Shift
C. No Shift
3. For a certain chemical reaction, ΔH∘=−156kJ. Assuming the reaction is at equilibrium, classify each of the following actions by whether it causes a leftward shift, a rightward shift, or no shift in the direction of the net reaction. Drag the appropriate items to their respective bins.
1) Decrease the temperature
2) Increase the temperature
A. Leftward Shift
B. Rightward Shift
C. No Shift

A - Increase (R), Decrease (P), Decrease(q), Triple both (Q) and (R)

B - Increase(P), Increase(q), Decrease (R)

C - Triple (P) and reduce (q) to one third

Explanation:

According to Le Chatelier principle, when a system is in equilibrium and one of the constraints that affect the rate of reaction is applied, the equilibrium will shift so as to annul the effects of the constraint.

P and Q are reactants, an increase in either or both without an equally measurable increase in R (a product) will shift the equilibrium to the right. Also, any decrease in R without a corresponding decrease in either or both of P and Q will shift the equilibrium to the right. Hence, Increase(P), Increase(q), and Decrease (R) will shift the equilibrium to the right.

In the same vein, any increase in R without a corresponding increase in P and Q will shift the equilibrium to the left. The same goes for any decrease in either or both of P and Q without a counter-decrease in R will shift the equilibrium to the left. Hence, Increase (R), Decrease (P), Decrease(q), and Triple both (Q) and (R) will shift the equilibrium to the left.

Any increase or decrease in P with a commensurable decrease or increase in Q (or vice versa) with R remaining constant will create no shift in the equilibrium. Hence, Triple (P) and reduce (q) to one third will create no shift in the equilibrium.