Endothermic And Exothermic Reactions Flashcards
what is an exothermic reaction?
a reaction that gives out heat e.g burning a piece of wood.
INCREASES TEMPERATURE
what is an endothermic reaction?
takes in heat energy, cool down + DECREASE IN TEMPERATURE e.g sherbet dissolving on your tongue
What is thermal decomposition?
breaking down of chemical using heat energy
e.g copper carbonate (green colour)—> copper oxide (black colour) + carbon dioxide
What is oxidation?
addition of oxygen
what is reduction?
removal of oxygen
what is a redox reaction?
reduction and oxidation both taking place in reaction.
what side of equation are oxidised materials always on?
the left hand side
give an example of a redox reaction and explain.
calcium + magnesium oxide —> calcium oxide + magnesium
calcium has been OXIDISED
it has gained oxygen therefore it has been oxidised
MgO has lost oxygen.
MgO has been reduced. This is reduction.
What is the thermite reaction? is it exothermic or endothermic, and what is it used for?
thermite reaction is iron oxide + aluminium.
It is exothermic.
It is used to weld train tracks together.
what colour are copper oxide and carbon?
both black powder
what happens when and after copper oxide and carbon are heated?
when heated mixture glows orange + gas is given off.
after heated, contents of boiling tube is coppery coloured solid.
what is the word equation for copper oxide + copper reaction and what type of reaction is it?
copper oxide + carbon —> copper + carbon dioxide
This is a REDOX REACTION as copper oxide is reduced to copper + carbon is oxidised to carbon dioxide, oxidation + reduction is taking place in the same reaction.
