Top 5 - Energy Changes

Question 1

True or False? In an Endothermic reaction heat is transferred to the outside.

Answer 1

False that would be an exothermic reaction.

Question 2

Name two different types of reactions which are exothermic.

Answer 2

Combustion

Neutralisation Reaction

Question 3

Give the equation for the thermal decomposition of calcium carbonate.

Answer 3

CaCO3 (+HEAT) = CO2 + CaO

Question 4

True or False? In an endothermic reaction, the products of the reaction have more energy than the reactants.

Answer 4

True

Question 5

What is the activation energy of a reaction?

Answer 5

The energy required for the reaction to take place.

Question 6

What is the activation energy?

Answer 6

The energy needed to start a chemical reaction.

The activation energy is used to break bonds so that the reaction can take place.

Question 7

What happens when the reaction gets the activation energy?

Answer 7

Energy taken in to break the bonds is endothermic

Energy is released when making new bonds which is

Question 8

How do you calculate the energy change?

Answer 8

Energy change = sum (bonds broken) - sum (bonds made)

Question 9

What is the energy change in an exothermic reaction?

Answer 9

A loss/release of energy