In this video we are going to look at exothermic and endothermic reactions. So what are they [how] are they different?
What about their energy levels in the next couple of minutes you'll know everything you need to get started
An exothermic reaction gives off energy to the [surroundings] like this fire giving off heat
Whereas an endothermic reaction takes in energy from its surroundings like this pool melting snowman taking in the heat
just remember Exo means external so giving out an
Endo means internal so taking in let's start by having a quick look
Because exothermic reactions transfer energy to the surroundings, [and] this energy is usually heat energy
They cause the surroundings to heat up. Just like a bonfire keeping everyone warm
Other examples of exothermic reactions are the neutralization reactions between acids and alkalis?
the reactions between water and calcium oxide and respiration
It is easy to detect exothermic reactions. Just get your thermometer and see if the temperature increases
Watch the hydrochloric acid and sodium hydroxide solution being mixed and see how the fellow meter increases
most chemical reactions are exothermic
Because heat is given our physical processes can also be endothermic or exothermic
When something freezes it goes from liquid to solid
Bonds need to be made for this to happen and to make bonds you need to do some work
Thus energy is given out and freezing is exothermic
Similarly when condensation happens because a gas is going to liquid
Again [bonds] need to be made and so energy is given out so freezing and condensation are both exothermic
Because in exothermic reactions energy is given out [to] the surroundings
This means that energy of the reactants is higher and the energy of [the] products hence the energy curve
For the exothermic reactions will look like this now
[let's] have a look at endothermic reactions. These are less common
Remember that endothermic reactions take in energy from the surroundings
Again as with exothermic reactions the energy being transferred is usually [heat]
So in endothermic reactions the surroundings usually get colder
Again, we can detect endothermic reactions with a thermometer because the temperature would get colder some examples of endothermic reactions are
electrolysis the reaction between sodium Carbonate and ethanoic acid and
photosynthesis
Endothermic reactions can also be seen in physical processes where something melts it goes from a solid to a liquid
For this to happen bonds need to be broken and to break bonds energy to be put in like our melting snowman
Boiling is also endothermic because energy needs to be put in to break the bonds for the liquid to turn to gas
because in endothermic reactions energy is added to the reaction the energy of the products is higher than the energy of the reactants and
So the energy curve looks like this, so there you have exothermic and endothermic reactions
all you need to remember is that exothermic reactions give out energy and
endothermic reactions take in energy
both can be detected with a thermometer in
Exothermic reactions the surroundings get hotter and in endothermic reactions the surroundings get colder
exothermic reactions start with more energy and end with less while endothermic reactions start with less energy and end with more
Freezing and condensation are exothermic because bonds need to be made which gives out energy
Melting and boiling are endothermic because bonds are broken which requires additional energy
think of the [snowman] again and finally
Exothermic reactions are more common