Emergetics Flashcards
What are exothermic reactions
Reactions that transfer energy to its surroundings
What is the defenutiom of an endothermic reaction
A reaction that takes in energy from its surroundings
What is the effects of exothermic reactions on surroundings temperature
Surrounding temperature increases
What is the effects of endothermic reaction on the surroundings
Surrounding temperature decreases
Examples of exothermic reactions
- combustion
- respiration
- neutralisation
Examples of endothermic reactions
- photosynthesis
- thermal decomposition
Why are certain chemical reactions used to heal wounds
Endothermic reactions can help absorb all of the heat from the wound
How to work out the energy change in reactions
E = MC(change in time)
Why would calculated values of energy change be different from the actual energy change
The energy could escape as heat, causing the calculated value to be higher than the real value
What is activation energy
The amount of energy that must be supplied to the reactants in other for the reaction to start
What is bond energy
Bond energy is the energy needed to break one mole of a particular bond
What type of reactions are breaking and making bonds
-Breaking bonds are endothermic, as energy is needed to overcome the existing forces between the Atoms in the molecule
-making bonds are exothermic, as energy is released when atoms move to a new, more stable form
What is bond energy measured in
kJ/mol
How to find bond energy
Energy in - energy out
When you get bond energy, and it is a negative number, what does it mean
That the reaction is exothermic, as it gives out energy and in turn looses its own energy
What is an oxidising agent (in terms of oxygen)
The one that gives oxygen to the other/ the one that gets reduced
Mg + CuO —> MgO + Cu
Copper is the oxidising agent as it initially has oxygen before the reaction
What is the reducing agent (in terms of oxygen)
It is the one which gains oxygen
Mg + CuO —> MgO + Cu
Mg is the reducing agent as it initially does not have oxygen before the reaction
What is an exothermic reaction in terms of energy
When more energy is released than is absorbed
What is an exothermic reaction in terms of energy
An exothermic reaction is when more energy is released to the surroundings than is absorbed by the reactions
