Energy changes

Question 1

What is an exothermic reaction

Answer 1

a reaction that release heat to the surroundings eg. combustion (burning)

Question 2

What is an endothermic reaction?

Answer 2

a reaction which takes in energy from the surroundings eg. electrolysis

Question 3

What does a reaction profile include?

Answer 3

the activation energy, which is the minimum energy needed by particles for a reaction to occur when they collide

Question 4

Is bond breaking endo or exothermic?

Answer 4

endothermic

Question 5

Is bond making endo or exothermic?

Answer 5

exothermic

Question 6

How do you calculate energy change in a reaction?

Answer 6

using average bond energies

Question 7

How do you calculate bond energies?

Answer 7

1.add together the bond energies for all bonds in a reactant(energy in)
2.add together bond energies for all the bonds in the product(energy out)
3.calcualte energy change=energy in-energy out

Question 8

What do chemical reactions in a cell produce?

Answer 8

electricity

Question 9

What do fuel cells use to produce electrical energy?

Answer 9

fuel and oxygen

Question 10

Where can hydrogen fuels cells be used?

Answer 10

in vechiles

Question 11

What is a redox reaction?

Answer 11

transfer of electrons between chemical species