1. What so you call the minimum amount of energy needed to start a chemical reaction?

a. activation energy
b. energy of the reaction
c. reaction mechanism energy
d. the entropy of reaction

2. which statement best describes the Collision theory?

a. All collisions lead to chemical reactions
b. most collisions lead to chemical reaction
c. very few reactions involve particle collisions
d. effective collisions lead to chemical reaction

3. which is/are necessary for successful collisions to occur?

I. Favourable collision geometry
II. Sufficient kinetic energy
III. Large change in enthalphy

a. I only
b. I and II only
c. II and III only
d. I, II, and III

4. which of the following will decrease the number of effective collisions during a chemical reaction?

a. adding a catalyst
b. Increasing the surface area
c. decreasing the temperature
d. Increasing reactant concentrations

5. which of the following will increase the reaction rate?

a. adding a catalyst
b. decreasing temperature
c. using lumps instead of powder
d. decreasing the concentration of an acid

6. crushing a solid into a powder will increase the reaction rate. why?

a. the particles will collide with more energy
b. the powered form has more surface area
c. the activation energy barrier will be lowered
d. the orientation of colliding particles will be removed

7. why does increasing the temperature of the reactants increase the reaction rate?

a. heat energy increases the size of the molecules of reactants, therefore the molecules react more frequently
b. heat energy helps to lower the amount of overall energy that is required for a reaction to occur
c. heat energy causes some of the reactants to evaporate, thereby increasing the concentration of the reactants
d. heat energy causes the particles of the reactant to move faster, therefore,react with each other more frequently

8. enzymes are an important component in the human body. most chemical reactions do not occur or will proceed slowly without enzymes. what are enzymes?

a. biological catalyst
b. simple elements
c. chemicals that increase the surface area
d. molecules used to increase concentration

9. how does a catalyst makes a chemical reaction faster?

a. it makes lower energy pathways available
b. it increases the concentration of products
c. it increases the concentration of the reactants
d. it binds to enzymes to release substrate

10. what happens to a catalyst in a chemical reaction?

a. it evaporates
b. it remains unchanged
c. it is incorporated into the reactants
d. it is incorporated into the products

11. which of the following substances act as a catalysts in the body?

a. carbohydrates
b. lipids
c. nucleic acid
d. enzymes

12. what is limiting reactant?

a. the reactant that makes the product
b. the reactant that is fully consumed prevents more products from being made
c. the reactant that is used up last and prevents more products from being made
dm the substance that is in excess that doesn't get used up as a reactant

13. for the reaction: C5H12 + 8 O2 > 5 CO2 + 6 H2O if 2 moles of C5H12 & 8 moles of O2 react, what is the limiting reactant?

a. C5H12
b. O2
c. CO2
d. H2O

14. consider the reaction in #13, how many moles of CO2 is produced in the reaction?

a. 5
b. 6
c. 7
d. 8

15. what is the mass of hydrogen gas (H2) formed when 25 grams of aluminium reacts with excess hydrochloric acid according to this balanced chemical equation:

2 AL + 6 HCl > 2AlCl3 + 3H2

(hint:)
[tex] \frac{1 }{1} h \: \frac{27}{13} al \: \frac{35}{17cl} [/tex]
a. 0.41 g
b. 1.2g
c. 1.8 g
d. 2.8 g​