Answer Key
Name:
Per:
Reaction Pathways Worksheet
1) Fill in the blanks on the reaction coordinate diagram
with the appropriate letters. Not all letters will be
used.
A) Reactants
B) Products
C) ∆H released
D) ∆H absorbed
2) Label the activation energy in the diagram.
catalyst
B
A
Ea
D
Specify whether the following is Endo or Exo:
3)
4)
5)
6)
Endo
Exo
Exo
Endo
The reaction in the diagram above.
The burning of wood to produce a hot flame.
4Fe + 3O2 —> 2Fe2O3 + Energy
A test tube that feels cold to the touch after two substances have been mixed.
7) Using the reaction pathway diagram in #1, draw a new curve that shows how a catalyst would affect the reaction
pathway.
Put an arrow up (↑) or an arrow down (↓) on the lines below to state whether the reaction rate will increase or decrease due to the action stated.
↓ Lowering the temperature of the reactants.
8)
9)
Dissolving two solids in water before mixing them together.
Diluting an aqueous solution of HCl with water before adding a piece of Magnesium.
11)
↓
↑
12)
↑
Adding an enzyme catalyst.
10)
Grinding a solid into smaller, fine particles.
Use the diagram to the left to answer the following:
13) Which letter represents EProducts?
14) Which letter represents EAC?
15) Which letter represents EReactants?
16) Which letter represents Ea?
17) Which letter represents ∆H?
18) Is the reaction endo or exo?
e
c
a
b
f
endo
HONORS ONLY 19-21:
19) Which letter represents Ea for the reverse rxn?
20) Which letter indicates ∆H for the reverse rxn?
21) Is the reverse reaction endo or exo?
d
f
exo
Use the diagram to the left to answer the following:
22) What is the value of EReactants?
23) What is the value of EProducts?
24) What is the value of EAC?
25) What is the value of Ea?
26) What is the value of ∆H?
27) Is the reaction endo or exo?
160
80
240
240-160 = 80
80-160 = -80
kJ
kJ
kJ
kJ
kJ
exo
HONORS ONLY 28-33: Answer for the reverse reaction.
28) What is the value of EReactants?
29) What is the value of EProducts?
30) What is the value of EAC?
31) What is the value of Ea?
32) What is the value of ∆H?
33) Is the reaction endo or exo?
80
160
kJ
kJ
240 kJ
240-80 = 160 kJ
160-80 = 80 kJ
endo
ALL: Create a potential energy diagram using the information provided. Then fill in the empty lines
34) EReactants = 350 kJ
Potential Energy Diagram
Ea = 100 kJ
450
EProducts = 250 kJ
350
∆H =
EAC =
250-350 = -100 kJ
350+100 = 450 kJ
35) EReactants = 200 kJ
400-200 = 200 kJ
EProducts = 150 + 200 = 350 kJ
Ea =
250
Potential Energy Diagram
400
350
∆H = + 150 kJ
200
EAC = 400 kJ
36) EReactants =
150-50 = 100 kJ
Ea = 300 kJ
EProducts = 150 kJ
Potential Energy Diagram
400
150
∆H = +50 kJ
EAC =
300+100 = 400 kJ
100