C6 Energy changes in chemical reactions Flashcards
1
Q
Describe the meaning of an exothermic reaction?
A
Energy is released from the system to the surroundings so the temperature increases.
2
Q
Define activation energy
A
The minimum quantity of energy which the reactants must possess in order to undergo a reaction.
3
Q
Describe the meaning of an endothermic reaction?
A
Energy is taken from the surroundings to the system so the temperature decreases.
4
Q
What type of reaction has a positive enthalpy change?
A
Endothermic
5
Q
What type of reaction has a negative enthalpy change?
A
Exothermic
