in this video we will learn about atom
economy what it shows and how to
calculate atom economy using
examples when a reaction is carried out
in Industry we are normally only
interested in one of the products the
other products are sometimes
waste atom economy simply shows us the
amount of product that was useful as a
percentage of all the products that were
formed the higher the atom economy the
less waste is
produced to carry out an atom economy
calculation we must look at our reaction
and the equation and use the molecular
masses remember we want to calculate the
amount of useful product as a percentage
of the total products so the equation
for this will be atom economy equals the
mass of the desired products divided by
the the mass of all the products
multiplied by 100 let's try an example
in this reaction we want to make one two
di
bromoethane by reacting bromine with
Ethan although we have not even
considered any molecular masses yet
pause the video and take a moment to
predict the atom economy in this
reaction where only one product is
formed
now let us carry out the
calculation one 12 Di bromoethane has a
molecular mass of
188 look at our equation the mass of the
useful product is
188 divided by a mass of all the
products
188 equals 1 multiplied by 100 equal
100%
the atom economy of this reaction is
100% which hopefully you predicted since
only one product is formed and therefore
there are no waste
products so now let's take a look at
calculating the atom economy of a
reaction with waste
products hydren is a useful Rocket Fuel
it can be made in the following
reaction pause the video now and attempt
to calculate the atom
economy firstly we must calculate the
molecular mass of each
compound
n2h4 has a molecular mass of
32 sodium chloride
58.5 and water H2O
18 first we need to identify our useful
product this is hydrogene N2 H4 it has a
mass of
32 the total sum of all the products
including hydrogen is
108.5
therefore the mass of our useful product
32 divided by mass of all the products
108.5 multiplied by 100 gives us an atom
economy of 29.5
this number is quite low and this
reflects the large amount of waste
product produced in water and sodium
chloride we could describe this reaction
as inefficient and a wasteful
reaction it is important that industry
Works towards the most efficient
industrial processes with high atom
economy as this is important for
sustainable
development a efficient processes
conserve natural resources and create
less
waste now at the end of this video you
should understand what Atom economy
shows and be able to calculate the atom
economy of a
reaction