A few AP CHEM exam questions

[jaehyung_91]

i have a take home "test" that my teacher allows me to use other resources including my book.

i really didnt understand kinetics.
can you explain to me by answering these questions?

4)(c) Provide a molecular explanation for the dependence of the rate of the forward reaction on the concentrations of the reactants.

(d) Provide a molecular explanation for the dependence of the rate of the forward reaction on temperature.

** and i also don't understand how to do an equilibrium graph:

PCl3(g) + Cl2(g) <===> PCl5(g)

Suppose that 2 moles of PCl3 and 1 mol of Cl2 are mixed in a closed container at constant temperature. Draw a graph that shows how the concentrations of PCl3, Cl2, and PCl5 change with time until after equilibrium has been firmly established.

(b) give the initial rate law for the forward reaction.


we didnt even learn equilibrium yet.


AND one last question:

can you explain to me

(c) Burning coal containing a significant amount of sulfur leads to "acid rain."


i have to do this during break, and my breaks done.

so pleeeeeease help me.

thank you very much.

 

[Gokul43201]

Pleeease read the Guidelines again (see my signature for link). We can't help you unless you show some effort first.

Does your textbook not have a chapter on kinetics and a chapter on equilibria?

 

[Blueshift5]

I am happy to help you understand these AP CHEM exam questions. Kinetics is the study of the rates of chemical reactions, and it is an important topic in chemistry because it helps us understand how fast reactions occur and what factors can affect their rates. Let's start by answering your first two questions about the molecular explanations for the dependence of the rate of the forward reaction on the concentrations of reactants and temperature.

4)(c) The rate of a chemical reaction is dependent on the concentrations of the reactants because the more reactant molecules there are, the more collisions there will be between them, increasing the likelihood of successful collisions that lead to a reaction. This can be explained by the collision theory, which states that for a reaction to occur, the reactant molecules must collide with enough energy and in the correct orientation. Therefore, when there is a higher concentration of reactants, there will be more collisions and thus a higher rate of reaction.

(d) The rate of a chemical reaction is also dependent on temperature because temperature affects the kinetic energy of the reactant molecules. When temperature increases, the reactant molecules move faster and have more energy, leading to more frequent and energetic collisions. This increases the chances of successful collisions and therefore increases the rate of reaction.

Regarding the equilibrium graph, it is important to understand that in a closed system, like the one described in the question, the concentrations of reactants and products will reach a point where they no longer change, known as equilibrium. The graph will show the concentrations of the reactants and products over time until they reach equilibrium.

For the initial rate law of the forward reaction, we can use the following equation: rate = k[PCl3]^x[Cl2]^y, where k is the rate constant and x and y are the reaction orders of PCl3 and Cl2, respectively. Since the reaction is in the gas phase, the concentration of each gas can be represented as partial pressure.

Finally, to explain the connection between burning sulfur-containing coal and acid rain, we need to look at the products of the combustion reaction. When sulfur burns, it forms sulfur dioxide (SO2) gas, which can react with water in the atmosphere to form sulfuric acid (H2SO4). This acid can then fall to the earth as acid rain, causing harm to plants, animals, and structures.

I hope this helps you understand these concepts better. Remember to always use your textbook and other resources