c7 Flashcards
what is an exothermic reaction
reactions that transfer energy to the surroundings
what does an exothermic reaction do to its surroundings
energy transferred increases the temperature of the surroundings
give some examples of exothermic reactions
respiration
neutralisation reaction
what happens to the products and reactants in an exothermic reaction
the products have less energy content than the reactants.
what is an endothermic reaction
a reaction that takes in energy from its surroundings.
what happens to the products and reactants in an endothermic reaction
the products have more energy content than the reactants
what do endothermic reactions do to the temperature
some decrease the temperature and other supply enough energy to keep the reaction going
give an example of an endothermic reaction
thermal decomposition
what can exothermic reactions be used for
hand warmers and self-heating cans
what reactions do hand warmers and self heating cans use
oxidation of iron
reaction of calcium oxide with water
what reactions do some other hand warmers and self heating cans use
use a reversible reaction such as crystallisation of salt, once used the pack can be put in boiling water to re dissolve the salt so it can be used again.
what can an endothermic reaction be used for
instant cold pack to be applied to injuries
what reaction does a cool pack use
ammonium nitrate and water that when the ammonium nitrate dissolves, takes in energy from the surroundings
what is activation energy
the minimum energy needed for the reaction to take place
draw and label both energy level diagrams
