Energy

Question 1

What is an exothermic reaction?

Answer 1

One which gives out energy to the surroundings, usually in the for of heat and usually shown by a rise in temp.

Question 2

What is an endothermic reaction?

Answer 2

One which takes in energy from the surroundings, usually in the form of heat and usually shown by a fall in temperature

Question 3

During a chemical reaction, old bonds are [ ] and new [ ] are formed

Answer 3

broken

bonds

Question 4

What is bond breaking? (Endo/Exo) Why?

Answer 4

Energy must be supplied to break existing bonds = endothermic

Question 5

What is bond formation? (Endo/Exo) Why?

Answer 5

Energy is released when new bond are formed = exothermic

Question 6

In an endothermic reaction, the energy required to break bonds is [ ] than the energy required when new bonds are formed

Answer 6

greater

Question 7

In an exothermic reaction, the energy required to break bonds is [ ] than the energy required when new bonds are formed

Answer 7

less

Question 8

How do you measure the amount of energy released by a chemical reaction?

Answer 8

By taking the temp of the reagents, mixing them in a polystyrene cup and measuring the temp. at the end of the reaction

Question 9

What is the biggest problem with energy measurements? How can you reduce this?

Answer 9

The amount of energy lost to the surroundings
By putting the polystyrene cup into a beaker of cotton wool to give more insulation, and putting a lid on the cup to reduce energy loss by evaporation