Regents Chemistry Test Preparation Practice Collision Theory

What is required for a chemical reaction to occur?*

(1) standard temperature and pressure

(2) a catalyst added to the reaction system

(3) effective collisions between reactant particles

(4) an equal number of moles of reactants and products

Two hydrogen atoms form a hydrogen molecule when*

(1) one atom loses a valence electron to the other atom

(2) one atom shares four electrons with the other atom

(3) the two atoms collide and both atoms gain energy

(4) the two atoms collide with sufficient energy to form a bond

A reaction will most likely occur if the colliding particles have the proper*

(1) mass, only

(2) mass and volume

(3) orientation, only

(4) orientation and energy

A chemical reaction is most likely to occur when the colliding particles have the proper*

(1) energy and orientation

(2) solubility and density

(3) ionic radii and mass

(4) atomic radii and volume

According to which theory or law is a chemical reaction most likely to occur when two particles with the proper energy and orientation interact with each other?*

(1) atomic theory

(2) collision theory

(3) combined gas law

(4) law of conservation of matter

An effective collision between reactant particles requires the particles to have the proper*

(1) charge and mass

(2) charge and orientation

(3) energy and mass

(4) energy and orientation

In the laboratory, a student investigates the effect of concentration on the reaction between HCl(aq) and Mg(s), changing only the concentration of HCl(aq). Data for two trials in the investigation are shown in the table below.

physical-behavior-of-matter, collision-theory, kinetics-equilibrium, collision-theory-and-the-rate-of-reaction, kinetics-equilibrium, rate-of-a-chemical-reaction fig: chem62015-exam_g9.png

Compared to trial 1, what is the expected reaction time for trial 2 and the explanation for that result?*

(1) less than 48 s, because there are fewer effective particle collisions per second

(2) less than 48 s, because there are more effective particle collisions per second

(3) more than 48 s, because there are fewer effective particle collisions per second

(4) more than 48 s, because there are more effective particle collisions per second

The collision theory states that a reaction is most likely to occur when the reactant particles collide with the proper*

(1) formula masses

(2) molecular masses

(3) density and volume

(4) energy and orientation

A chemical reaction occurs when reactant particles*

(1) are separated by great distances

(2) have no attractive forces between them

(3) collide with proper energy and proper orientation

(4) convert chemical energy into nuclear energy

Which statement explains why increasing the temperature increases the rate of a chemical reaction, while other conditions remain the same?*

(1) The reacting particles have less energy and collide less frequently.

(2) The reacting particles have less energy and collide more frequently.

(3) The reacting particles have more energy and collide less frequently.

(4) The reacting particles have more energy and collide more frequently.

Base your answers to questions 11 on the information below.

Several steps are involved in the industrial production of sulfuric acid. One step involves the oxidation of sulfur dioxide gas to form sulfur trioxide gas. A catalyst is used to increase the rate of production of sulfur trioxide gas. In a rigid cylinder with a movable piston, this reaction reaches equilibrium, as represented by the equation below.

2SO₂(g) + O₂(g) ⇌ 2SO₃(g) + 392 kJ

Explain, in terms of collision theory, why increasing the pressure of the gases in the cylinder increases the rate of the forward reaction.*

Base your answers to questions 12 on the information below and on your knowledge of chemistry.

Carbon monoxide, CO(g), is a toxic gas found in automobile exhaust. The concentration of CO(g) can be decreased by using a catalyst in the reaction between CO(g) and O₂(g). This reaction is represented by the balanced equation below.

physical-behavior-of-matter, collision-theory, kinetics-equilibrium, collision-theory-and-the-rate-of-reaction, kinetics-equilibrium, rate-of-a-chemical-reaction fig: chem12017-exam_g16.png

Explain, in terms of collision theory, why an increase in temperature increases the rate of the reaction.*

Base your answers to questions 13 on the information below and your knowledge of chemistry.

Methanol can be manufactured by a reaction that is reversible. In the reaction, carbon monoxide gas and hydrogen gas react using a catalyst. The equation below represents this system at equilibrium.

CO(g) + 2H₂(g) ⇌ CH₃OH(g) + energy

Explain, in terms of collision theory, why increasing the concentration of H₂(g) in this system will increase the concentration of CH₃OH(g).*

Base your answers to questions 14 on the information below and on your knowledge of chemistry.

Millions of tons of ammonia are produced each year for use as fertilizer to increase food production. Most of the hydrogen needed to produce ammonia comes from methane gas reacting with steam. This reaction, which occurs in a container under controlled conditions, is shown below in unbalanced equation 1.

Equation 1: CH₄(g) + H₂O(g) + energy → CO(g) + H₂(g)

The reaction that produces ammonia is represented by balanced equation 2, shown below. A catalyst can be used to increase the rate of the reaction.

Equation 2: N₂(g) + 3H₂(g) → 2NH₃(g) + energy

A potential energy diagram for equation 2 is shown below.

moles-and-stoichiometry, chemical-reactions-and-equations fig: chem82017-exam_g20.png

Explain, in terms of collision theory, why an increase in temperature increases the rate of reaction between methane gas and steam.*

Explain, in terms of collisions, why increasing the surface area of the hot carbon increases the rate of the forward reaction.*