C5 Flashcards
what is an exothermic reaction?
a reaction where energy is transferred to the surroundings
what is an endothermic reaction?
a reaction where energy is taken in from the surroundings
what happens to the temp of the surroundings in an exothermic/ endothermic reaction?
exothermic: increases
endothermic: decreases
what are 5 examples of exothermic reaction?
- neutralisation
- combustion
- respiration
- rusting
- oxidation
- hand warmer
- self heating can
what are 3 examples of endothermic reactions?
- photosynthesis
- thermal decomposition
- ice packs
n.d polystyrene cup practical
practical - why was a polystryene cup used?
to reduce the heat/ energy transfer lost to the surroundings
practical - why was the polystyrene cup placed in a beaker?
to make it more stable, so it doesn’t fall over
practical - why was the lid used to cover the cup?
to reduce heat lost to the surroundings from the surface
practical - why was the experiment repeated?
so you can identify any anomalies and calculate a mean
what 2 things does chemical reactions involve?
breaking and making bonds
where are bonds broken?
in the reactants
where are bonds formed?
in the products
what do atoms in a reaction do?
rearrange to make something new
is breaking bonds exothermic or endothermic?
endothermic
- requires energy
