Collision Theory: Factors Affects the Rate of Reactions

1.  What factor affect the slow cooking of the barbeque?

• temperature

• surface area

• concentration

• catalyst

2. What is a catalyst?

• A substance added to slow down the chemical reaction.

• A substance that speeds up the rate of reaction by lowering the activation energy.

• A substance added to form hydrogen bond and speed up the rate of chemical reaction.

• A substance added to disrupt the bonded atoms.

3. Grains of sugar have a greater _______ than a solid cube of sugar of the same mass, and therefore will dissolve quicker in water

• Surface area

• Temperature

• Catalyst

• Concentration

4. Explain why the temperature of reaction increases and the rate of reaction increases as well?

• The particles are in contact and have less activation energy.

• The activation energy is decreased

• The reactant molecules collide more frequently and with high energy per collision.

• The reactant molecules collide less frequently and with low high energy per collision.

5. Which of the following best describe the effect of catalysts in reaction rate?

• They lower the activation energy and speed up the reaction

• They increase the free energy of the reaction

• They are the reacting molecules that become products

• They are the products formed after a reaction

What happens to a catalyst at the end of a reaction?

• It breaks in reaction.

• It is regenerated in reaction

• It escapes as a gaseous product.

• It becomes an unrecyclable by-product.

7. Which of the following describes catalyzed and uncatalyzed reaction pathways?

• The catalyzed reaction has a lower activation energy and faster the reaction rates than the uncatalyzed reaction.

• The catalyzed and uncatalyzed reactions form products with equal energies.

• The catalyzed reaction produces a product with lower energy than the uncatalyzed reaction.

• The catalyzed and uncatalyzed reactions follow the same reaction pathways.

8. Which of the following defines heterogenous catalysis?

• Catalyst with the same phase as the reactant. Usually in Aqueous state.

• Catalyst with different phase as the reactant. Usually solid state.

• It is the increase in the rate of a process by a biological molecule, an "enzyme

• Catalyst can operate by increasing the number of effective collisions.

9. Explain why does a higher concentration increase the rate of reaction?

• It increased the amount of reactants

• It lowers the activation energy

• It increases the energy of particle collisions

• It increases the frequency of particle collisions

10. In this situation, grinding a seltzer tablet into powder increase the rate of reaction due to increased, what factors that affect the rates of reactions occur?

• surface area

• concentration

• catalyst

• temperature