C3.2 Flashcards
What is an exothermic reaction
If the temperature of a reaction mixture increases during a chemical reaction, the reaction is an exothermic one.
What is an endothermic reaction
If the temperature of the reaction mixture decreases during a chemical reaction the reaction is an endothermic one.
What happens in a chemical reaction
Bonds break in the reactants to produce separate atoms and then new bonds form between the atoms to make the products.
What does making bonds do
Releases energy
What does breaking bonds do
Taking in energy
What is activation energy
The minimum energy required for a reaction to start.
In an endothermic reaction what happens in terms of bonds
In an endothermic reaction the energy is transferred to break bonds is greater than the energy transferred to the surroundings when new bonds form. Positive energy change.
What does an endothermic reaction profile look like
DRAW IT
In an exothermic reaction what happens
In an exothermic reaction the energy transferred to break bonds is less than is transferred to the surroundings when bonds form. Negative energy change
What does an exothermic reaction profile look like
DRAW IT
What is energy transferred to break bonds
It is a positive energy change
What is energy transferred to make bonds
It is a negative energy change
Formula for energy change
Total energy = Energy transferred to break bonds - Energy transferred to make bonds.
