6.2 Factors Affecting Rxn Rates

Question 1

Chemical properties affect the
_________ and _________ of a
substance in a chemical reaction

Answer 1

behaviour; reactivity

Question 2

Higher concentration of reactants leads to
an _______ rate of reaction

Answer 2

increased

Question 3

Higher concentration means that there are
more ________ molecules available to
_______ with each other

Answer 3

reactant; collide

Question 4

Only atoms or ions at the surface of a substance react (as they interact with other reactants)

Therefore, if we cut or grind reacting substances into ________ pieces (creating more ______), we can _________ the rate of the chemical reaction

Answer 4

smaller; surfaces; increase

Question 5

_______ is a measure of the average kinetic
energy of molecules

Answer 5

Temperature

Question 6

The more ______ energy reacting molecules have, the _______ and further they will move (higher energy)

This leads to more ________ between reacting
molecules, allowing more reactant molecules to convert to _______

Answer 6

kinetic; faster; collisions; product

Question 7

Catalyst

Answer 7

Substance that alters the rate of a chemical reaction without itself being permanently changed

Question 8

Catalysts lower __________ ________ by providing
alternative mechanisms and transitions states

Answer 8

activation energy

Question 9

__________ catalysts exist in a different state of
matter from the reactants, whereas __________ catalysts exist in the same physical state as the reactants

Answer 9

Heterogeneous; homogenous

Question 10

biological catalyst

Answer 10

a catalyst made by a living system

Question 11

When reactants are in different states of matter, an increase in reactant surface
area ________ the rate of a reaction.

Answer 11

increases

Question 12

In each example below, identify the factor that
affects the reaction rate.
(a) Copper metal will turn green over time.

Answer 12

nature of reactant

Question 13

In each example below, identify the factor that
affects the reaction rate.
(b) Milk can last several weeks when refrigerated, but will quickly sour at room temperature.

Answer 13

temperature

Question 14

In each example below, identify the factor that
affects the reaction rate.
(c) The dust in coal mines has been known to
explode, whereas whole chunks of coal are
difficult to ignite.

Answer 14

surface area

Question 15

In each example below, identify the factor that
affects the reaction rate.
(d) Magnesium metal is not used to make pipes.

Answer 15

nature of reactant

Question 16

In each example below, identify the factor that
affects the reaction rate.
(e) Zeolite is added to large-chain hydrocarbons,
causing them to break down into smaller, more
useful molecules. The zeolite is then removed
and reused.

Answer 16

catalyst

Question 17

In each example below, identify the factor that
affects the reaction rate.
(f) Hydrogen peroxide (3 %) purchased in the
drugstore is safe to put on open cuts. Hydrogen
peroxide (30 %) purchased for the lab can cause
very severe burns.

Answer 17

concentration

Question 18

In each example below, identify the factor that
affects the reaction rate.
(g) A glow stick will glow longer when placed in
the freezer.

Answer 18

temperature

Question 19

In each example below, identify the factor that
affects the reaction rate.
(h) Signs warn about the dangers of having sparks
or open flames near flammable fuels.

Answer 19

temperature

Question 20

In each example below, identify the factor that
affects the reaction rate.
(i) Flour mills ban smoking due to the high
probability of explosions.

Answer 20

surface area

Question 21

In each example below, identify the factor that
affects the reaction rate.
(j) Phenylketonuria is a genetic disorder in
which the body cannot produce the enzyme
phenylalanine hydroxylase. People with
this disorder cannot digest phenylalanine, a
common amino acid.

Answer 21

catalyst