Energy transfers Flashcards
(11 cards)
Law of conservation of energy
Energy cannot be created nor destroyed
2 types of chemical reactions
exothermic and endothermic
What do exothermic reactions do? Give examples of exothermic reactions.
Transfer energy to surroundings.
Combustion
Many oxidation reactions
Neutralisation
What do endothermic reactions do? Give examples of endothermic reactions.
Absorb energy from surroundings
Thermal decomposition
Photosynthesis
What is a reaction profile
Shows the amount of energy stored
What is the transition state
The point in a reaction where the highest amount of energy is stored
How to work out overall energy change? How can we tell if this reaction is exothermic or endothermic?
Draw all molecules involved
Add total energy taken in (reactants) and energy released (products)
Subtract energy released from energy taken in
Negative = exothermic
Positive = endothermic
Cells contain chemicals which _____.
react to produce electricity
What does the voltage produced by a cell depend on?
Type of electrode, type of electrolyte, etc
How can a simple cell be made
Connecting two different metals in contact with an electrolyte
Reduction occurs at the _____.
Oxidation occurs at the _____.
cathode
anode
