Energy

Created by: Lily04
Created on: 10-06-17 17:00

Explain the difference between exothermic and endothermic reactions

EXOTHERMIC reactions RELEASE energy to the surroundings and cause a TEMPERATURE RISE. ENDOTHERMIC reactions ABSORB energy from the surroundings and cause a TEMPERATURE DROP.

1 of 10

Explain the calorimetry experiment. What is it used to measure?

Can be used to measure the energy released by a fuel: A calorimeter can be used to compare the amounts of heat energy released by the combustion of different fuels. Water is heated by a bottled gas burner/spirit burner in a copper calorimeter.

2 of 10

In terms of bonds, what happens in an exothermic reaction?

bonds are MADE

3 of 10

In terms of bonds, what happens in an endothermic reaction?

bonds are BROKEN

4 of 10

Explain why a reaction is exothermic using the idea of energy changes during bond making and breaking

Chemical reactions that release more energy when making bonds than breaking them are EXOTHERMIC reactions.

5 of 10

Explain why a reaction is endothermic using ideas of energy changes during bond making and breaking

Chemical reactions that need more energy to break bonds than released when new bonds are made are ENDOTHERMIC reactions.

6 of 10

Give the formula for ENERGY TRANSFER in Joules

m x c x ^T (mass of water heated (g) x specific heat capacity (J/g/degrees Celsius) x change in temp

7 of 10

How can you compare fuels?

by working out the amount of energy transferred by the fuel to the water in the calorimetry experiment

8 of 10

How would you calculate the energy released per gram of fuel (in the calorimetry experiment)?

measure the mass of the spirit burner before and after the experiment, and see the difference.

9 of 10

Energy per gram = ?

energy supplied (J) / mass of fuel burned

10 of 10

Other cards in this set

Card 2

Front

Explain the calorimetry experiment. What is it used to measure?

Back

Card 3

Front

In terms of bonds, what happens in an exothermic reaction?

Back

Card 4

Front

In terms of bonds, what happens in an endothermic reaction?

Back

Card 5

Front

Explain why a reaction is exothermic using the idea of energy changes during bond making and breaking

Back

View more cards

Similar Chemistry resources:

See all Chemistry resources »

See all Energy of reactions/Exothermic and endothermic reactions resources »

Get Revising

Energy