POST LABORATORY DISCUSSION

Question 1

Rate of reaction

Answer 1

describes how fast
reactants are used up and products are
formed

Question 2

Collision Theory

Answer 2

For a chemical reaction to take place, there must
be collisions among the atoms, ions, molecules
with sufficient energy and proper orientation

Question 3

Activation energy (Ea)

Answer 3

is the minimum
amount of energy required to initiate a
chemical reaction

Question 4

Chemical kinetics

Answer 4

is the study of rates
of chemical reactions, the factors that
affect reaction rates, and the mechanisms
by which reactions occur

Question 5

Factors that affect reaction rates

Answer 5

Nature of reactants
 Rate of rxns depends on the surface areas
or degree of subdivision

Concentration
 Rate = # of collisions divided by s

Temperatures
◦ Average kinetic energy (KE) of molecules is
proportional to the temperature- Arrhenius
equation

Catalyst
◦ Catalyst- are substances that can be
added to reaction mixtures to increase
the rate of reaction

Question 6

1. What effect does concentration have on the
   rate of a chemical reaction? Explain

Answer 6

1. The rate of a chemical reaction
   increases as the concentration increases
   (directly proportional)
   ◦ This is due to a greater number of particles
   present in solution which increases the
   probability of a collision to take place and thus
   increases the probability of a chemical reaction
   to take place

Question 7

2. What effect does the temperature have on the
   rate of a chemical reaction? Explain

Answer 7

2. Increasing the temperature of a system
   increases the rate of chemical reaction
   (directly proportional)
   ◦ Since the increase in temperature is an
   increase in the average kinetic energy of the
   particles, there is an increase in the probability
   for a collision to take place between particles
   and thus increases the probability of a chemical
   reaction to take place

Question 8

3. What effect does a catalyst have on the rate of
   a chemical reaction? Explain

Answer 8

3. The addition of a catalyst increases the
   rate of a chemical reaction (directly
   proportional)
   ◦ This is due to the fact that, a catalyst presents
   alternate pathways for a chemical reaction to
   take place

Question 9

4. How does activation energy affect reaction
   rate? Explain

Answer 9

4. Inversely proportional
   ◦ Larger amount of activation energy- decrease
   reaction rate
   ◦ Smaller amount of activation energy- increase
   reaction rate

Question 10

Chemical rxns that can occur in either
direction are called

Answer 10

REVERSIBLE RXNS

Question 11

Chemical equilibrium exists when 2
opposing rxns occur simultaneously at the
same rate

Answer 11

◦ If a system at equilibrium is distributed by
changing its conditions (applying a stress), the
system shifts in the direction that reduces the
stress- Le Chatelier’s

Question 12

 3 types of changes that can disturb the
equilibrium of a rxn:

Answer 12

◦ 1. Changes in concentration
◦ 2. Changes in temperature
◦ 3. Changes in pressure or volume (rxns that
involves gases)