Textbook Question
The equilibrium constant Kp for the reaction PCl51g2 ∆ PCl31g2 + Cl21g2 is 3.81 * 102 at 600 K and 2.69 * 103 at 700 K.(b) How are the equilibrium amounts of reactants and products affected by (iii) addition of a catalyst?
Ch.15 - Chemical Equilibrium
Chapter 15, Problem 128
The following reaction is important in gold mining: 4 Au1s2 + 8 CN-1aq2 + O21g2 + 2 H2O1l2 ∆ 4 Au1CN22-1aq2 + 4 OH-1aq2For a reaction mixture at equilibrium, in which direction would the reaction go to reestablish equilibrium after each of the following changes?(a) Adding gold
Verified step by step guidance1
insert step 1> Identify the reaction and its components. The given reaction is: 4 Au_{(s)} + 8 CN^-_{(aq)} + O_2_{(g)} + 2 H_2O_{(l)} \rightarrow 4 Au(CN)_2^-_{(aq)} + 4 OH^-_{(aq)}.
insert step 2> Recognize that the reaction is at equilibrium, meaning the rate of the forward reaction equals the rate of the reverse reaction.
insert step 3> Apply Le Chatelier's Principle, which states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change.
insert step 4> Consider the effect of adding gold (Au) to the system. Since gold is a reactant, adding more gold will shift the equilibrium to the right to produce more products, in order to reduce the concentration of gold.
insert step 5> Conclude that the addition of gold will cause the reaction to shift towards the formation of more Au(CN)_2^- and OH^- ions, thus moving the equilibrium to the right.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Le Chatelier's Principle
Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change. This principle helps predict how a system at equilibrium will respond to changes in concentration, pressure, or temperature, allowing us to determine the direction in which the reaction will shift.
Recommended video:
Guided course
07:32
Le Chatelier's Principle
Equilibrium Constant (K)
The equilibrium constant (K) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a given reaction at a specific temperature. It provides insight into the extent of the reaction and helps in understanding how changes in concentration affect the position of equilibrium.
Recommended video:
Guided course
01:14Equilibrium Constant K
Reaction Quotient (Q)
The reaction quotient (Q) is a measure of the relative concentrations of products and reactants at any point in a reaction, not just at equilibrium. By comparing Q to K, one can determine the direction in which the reaction will shift to reach equilibrium: if Q < K, the reaction shifts right (toward products), and if Q > K, it shifts left (toward reactants).
Recommended video:
Guided course
00:49Reaction Quotient Q
Related Practice
Textbook Question
Baking soda (sodium bicarbonate) decomposes when it is heated:2 NaHCO31s2 ∆ Na2CO31s2 + CO21g2 + H2O1g2ΔH° = + 136 kJConsider an equilibrium mixture of reactants and products in a closed container. How does the number of moles of CO2 change when the mixture is disturbed by the following:(b) Adding water vapor