Reaction Rates

Question 1

Heat of reaction and diagram for endothermic

Answer 1

H > 0
__
Diagram: / \
|
__/

Question 2

Heat of reaction and diagram for exothermic

Answer 2

H < 0
__
Diagram: __/ \
|
\___

Question 3

When a bond is broken what happens to the energy and exo or endo

Answer 3

Endothermic and energy is absorbed

Question 4

When a bond is formed what happens to the energy and exo or endo

Answer 4

Exothermic and energy is released

Question 5

What influence does Increase temp have on reaction rate in

Answer 5

Increased average Ek of the particles

Question 6

What influence does increased concentration have on reaction rate

Answer 6

Increased no. Of particles

Question 7

What influence does increased surface area have on reaction rate

Answer 7

Increased no. of collisions per unit time

Question 8

What influence does increased pressure have on reaction rate

Answer 8

Increased concentration of particles

Question 9

What are the units of reaction rate

Answer 9

Mol/dm/s

Or

Mol. dm^-1. s^-1

Question 10

Label energy graph

Answer 10

• Left hand side = potential energy
• Bottom = reaction progress
• ___ reactants first then ___ products
• activation energy measured from reactants - activated complex
• activated complex = peak of graph
• heat of reaction is difference between reactants and products

• if reactants are lower than products = endothermic
• if products are lower than reactants = exothermic