Answer to Question #158832 in General Chemistry for Kimberly

Question

1. Based on the ​nature of the reactants​ in each of the equations below, which reaction at 25°C will occur at the fastest rate?

(1) C(s) + O​2​ (g) → CO​2​ (g)

(2) NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

(3) CH​3O​ H(l) + CH​3C​ OOH(l) → CH​3C​ OOCH​3(​ aq) + H​2O​ (l) (4) CaCO​3(​ s) → CaO(s) + CO​2​(g)

2. In an experiment involving a reaction, it was found that an increase in temperature increased the rate of the reaction. Explain this result in terms of collision theory.

3. Which event must ​always ​occur for a chemical reaction to take place? (1) formation of a precipitate

(2) formation of a gas

(3) effective collisions between reacting particles

(4) addition of a catalyst to the reaction system

Given the equation for a reaction at equilibrium:

2SO2 (g) + O2 (g) —> 2SO3 (g) + Energy

4. Explain, in terms of collisions between molecules, why increasing the concentration of O​2 (​ g) produces a ​decrease i​ n the concentration of SO​2​ (g).

Answer 1

1. Based on the ​nature of the reactants​ in each of the equations below, which reaction at 25°C will occur at the fastest rate?

Answer: (2) NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l) – occurs immediately, all substances are in the ionic form.

2. In an experiment involving a reaction, it was found that an increase in temperature increased the rate of the reaction. Explain this result in terms of collision theory.

Answer: Increase in temperature causes the molecules to collide with greater energy, thus the formation of products is more favorable.  

3. Which event must ​always ​occur for a chemical reaction to take place?

Answer: (3) effective collisions between reacting particles.

4. Given the equation for a reaction at equilibrium: 2SO2 (g) + O2 (g) —> 2SO3 (g) + Energy

Explain, in terms of collisions between molecules, why increasing the concentration of O​2 (​ g) produces a ​decrease i​n the concentration of SO​2​ (g).

Answer: as more oxygen added to the system, more product is formed as a result, and it uses more SO2(g) in this process.