C7.1 - Exothermic And Endothermic Reactions (Finished) Flashcards
What is the name of reactions that transfer energy to the surroundings from the reacting chemicals?
Exothermic reactions
What is the energy transfer in endothermic reactions?
Energy from the surroundings is transferred to the reactants
The products of an exothermic reaction have a ___ energy content than the ___.
Lower, reactants
How common are endothermic reactions?
Much less common than exothermic ones
What are differences in energy in reactions expressed in?
kilojoules per mole KJ/mol
What would you use to investigate temperature changes?
A thermometer
In endothermic reactions do the reactants have a higher energy content than products?
No, products have more energy than reactants
Why is energy transferred in chemical reactions?
Chemicals store a certain amount of energy. When chemical reactions take place, chemical bonds in the reactants are broken and new ones made in the products so energy is transferred
What is burning fuels (combustion) an example of?
Burning fuels (combustion) is an example of an exothermic reaction
Give 3 examples of exothermic reactions?
- burning fuels (combustion)
- Neutralisation reaction (acid + alkali)
- Many oxidation reactions are exothermic
Give 2 uses of exothermic reactions?
- some hand warmers use exothermic oxidation of iron in air (+ salt solution catalyst)
- Self heating cans
Give an exampleof endothermic reactions?
- Reaction between citric acid and sodium hydrogencarbonate
- Thermal decomposition (e.g. heating calcium carbonate causes it to decompose into calcium oxide and co2)
Give a use of endothermic reactions?
In sports injury packs (cooling packs)
