For the following equilibrium system, which of the changes...

For the following equilibrium system, which of the changes will form more $\mathrm{CaCO}_{3} ?$ $\mathrm{CO}_{2}(g)+\mathrm{Ca}(\mathrm{OH})_{2}(s) \rightleftharpoons \mathrm{CaCO}_{3}(s)+\mathrm{H}_{2} \mathrm{O}(l) \\ \quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad \Delta H^{\circ}=-113 \mathrm{kJ}$ (a) Decrease temperature at constant pressure (no phase change) (b) Increase volume at constant temperature (c) Increase partial pressure of $\mathrm{CO}_{2}$ (d) Remove one-half of the initial $\mathrm{CaCO}_{3}$

For the following equilibrium system, which of the changes will form more $\mathrm{CaCO}_{3} ?$
$\mathrm{CO}_{2}(g)+\mathrm{Ca}(\mathrm{OH})_{2}(s) \rightleftharpoons \mathrm{CaCO}_{3}(s)+\mathrm{H}_{2} \mathrm{O}(l) \\ \quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad \Delta H^{\circ}=-113 \mathrm{kJ}$
(a) Decrease temperature at constant pressure (no phase change)
(b) Increase volume at constant temperature
(c) Increase partial pressure of $\mathrm{CO}_{2}$
(d) Remove one-half of the initial $\mathrm{CaCO}_{3}$

Key Concepts

Le Chatelier's Principle

Le Chatelier's Principle is the core concept used to predict how a system at equilibrium responds to external changes. According to this principle, if a disturbance (such as changes in concentration, pressure, or temperature) is applied to an equilibrium system, the system will shift in a direction that counteracts the disturbance, thereby partially offsetting the change.

Effect of Temperature on Equilibrium

Temperature is a critical factor in influencing chemical equilibria, particularly for reactions that are exothermic or endothermic. In exothermic reactions, where heat can be considered as a product, reducing the temperature favors the formation of products, while in endothermic reactions, increased temperature shifts equilibrium toward the products. Understanding this interplay helps predict the effect of temperature changes on the yield of a reaction.

Effect of Pressure and Volume Changes on Equilibrium

Pressure and volume changes can significantly affect the position of equilibrium in reactions involving gases. When the volume increases (or the pressure decreases), the equilibrium shifts toward the side with more moles of gaseous substances to restore pressure balance. Conversely, a decrease in volume (increase in pressure) will shift the equilibrium toward the side with fewer gaseous moles. This concept is crucial in managing reactions where gaseous reactants or products are involved.

Effect of Composition Changes on Equilibrium

Changes in the amount of a reactant or product can disturb an equilibrium system. For instance, changing the partial pressure or concentration of a gaseous component will cause the system to adjust in order to re-establish equilibrium. Adding more reactant typically drives the reaction forward to produce more product, while removing a product can also shift the equilibrium toward product formation. This concept helps in understanding how targeted changes in system composition influence the overall reaction.

Transcript

00:01 We have this chemical reaction, and in parts a through d, we are given different disturbances that we are imposing on this system, and we want to use lashat -layer's principle in order to determine which one of these disturbances will cause the reaction to respond by shifting to the right to form our product.

00:18 The reason we want to form our product is because we're interested in which one of these changes will lead to an increase in the formation of caco3.

00:27 So in part a, the disturbance is a decrease in temperature.

00:32 If we look at the problem statement, we notice that we are given a negative value for the sign of delta h, the change in enthalpy.

00:39 And that means that we have an exothermic reaction and that heat can be written as a product.

00:46 Remember that for exothermic reactions, if we were to increase the temperature, then the reactants would be favored.

00:54 And conversely, if we were to decrease the temperature of the system, which is what we are doing in part a, then the products are favored.

01:00 So since this is an exothermic reaction and we are decreasing the temperature, we know that more product will be formed, which will increase the formation of caco3 since it is a product.

01:13 So part a is a disturbance that will increase the formation of caco3.

01:19 At part b, we want to know what would happen if we increase the volume of the container in which this reaction occurs.

01:26 Remember that the volume is inversely related to the pressure.

01:30 So when we increase the volume, we are really decreasing the pressure.

01:33 And that means the system will respond by increasing the pressure.

01:37 The pressure is related to the total number of moles of gas in the system.

01:42 If we looked at the reactant side, we see that we just have one mole of gas of co2, and we have no gases species on the product side.

01:51 So we have one mole of gas on the reactant side...