Kinetics and equilibrium retake test again :)

2. As the number of effective collisions between reacting particles increases, the rate of reaction

• decreases

• increases

• remains the same

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

• formation of a precipitate

• formation of a gas

• effective collisions between reacting particles

• addition of a catalyst to the reaction system

As the temperature of a reaction increases, it is expected that the reacting particles collide

• more often and with greater force

• more often and with less force

• less often and with greater force

• less often and with less force

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

• The reacting particles have less energy and collide less frequently.

• The reacting particles have less energy and collide more frequently.

• The reacting particles have more energy and collide less frequently

• The reacting particles have more energy and collide more frequently.

Given the reaction:

Zn(s) + 2 HCI(aq) --> Zn2+(aq) + 2 Cl–(aq) + H2 (g)

If the concentration of HCl(aq) is increased, the frequency of reacting collisions will

• decrease, producing a decrease in the reaction rate

• decrease, producing an increase in the reaction rate

• increase, producing a decrease in the reaction rate

• increase, producing an increase in the reaction rate

Which statement explains why the speed of some chemical reactions is increased when the surface area of the reactant is increased?

• This change increases the density of the reactant particles.

• This change increases the concentration of the reactant.

• This change exposes more reactant particles to a possible collision.

• This change alters the electrical conductivity of the reactant particles.

According to Reference Table I, which gas is formed from its elements as a result of an endothermic reaction?

• CO2

• NO2

• H2O

• C2H6

.Given the balanced equation representing a reaction: CH4(g) + 2O2(g )--> CO2(g) + 2H2O(g) + energy Which change in reaction conditions will increase the frequency of effective collisions between reactant molecules?

• decreasing the pressure of the reactants

• decreasing the temperature of the reactants

• increasing the concentration of the reactants

• increasing the volume of the reactants

.Beaker A contains a 1 gram piece of zinc and beaker B contains 1 gram of powdered zinc. If 100 milliliters of 0.1 M HCl is added to each of the beakers, how does the rate of reaction in beaker A compare to the rate of reaction in beaker B?

• The rate in A is greater due to the smaller surface area of the zinc.

• The rate in A is greater due to the larger surface area of the zinc.

• The rate in B is greater due to the smaller surface area of the zinc.

• The rate in B is greater due to the larger surface area of the zinc.

An increase in the surface area of reactants in a heterogeneous reaction will result in

• a decrease in the rate of the reaction

• an increase in the rate of the reaction

• a decrease in the heat of reaction

• an increase in the heat of reaction