Tip:
Highlight text to annotate it
X
Chemical equations are fundamental to understanding chemistry
chemists use chemical equations to describe or actions
in order to understand a reaction
a chemical reaction you need to write a chemical equation properly
now let's look at this reaction this is
what's called a thermite reaction what is happening here
is iron oxide or rust is reacting with aluminum
now to produce iron pure iron an aluminumoxide
now this reaction so violent
so hot it actually
melts the iron so the chemical equation for this
is fe2 oxide
plus aluminum on the reactive side or the left side the arrow
and it produces iron
liquid plus aluminum oxide
solid on the product side of the equation
now this
is an example of how all equations are outlined reactives on the left side of arrow
products on the right side a row
the state symbols are
next to the the compounds i should say what they were in
the reaction so iron oxide was solid aluminum was solid
producing a liquid iron and a solid
oxide however this equation has one fatal
flaw it's unbalanced what i mean by unblalanced
is one the laws of chemistry is the law of conservation of mass
mass cannot be created and/or destroyed so what this means for chemical
equations
is that if it's on one side of the arrow it needs to be on the other side of the arrow
so for example look at the iron iron
in iron oxide we have two irons but on the products I we only have one iron
atom
so this is unbalanced equation
let's go through this and actually balance it
so as I said we only have one iron on the product side but if we put a two
in front of it
coefficient we're left with two irons on the product side two irons on the
reactive side that's balanced we have 3 oxygen's on
the reactive side and three on the product side
the oxygen's are balanced aluminum we have two aluminum on the product side
however really a one aluminum on the reactive side by putting a two coefficient of
in front of the aluminum
we now have a balanced equation
now what's have an example of another
a chemical reaction Nitrogen Triiodide
this is a very unstable compound it wants to decompose
very violently so for example
by just touching it with this feather
the solid actually explodes so
the chemical equation for this reaction
is a nitrogen triioxide
decomposes to nitrogen and iodine
now for practice balance this equation
and when we come back we will go through it
to see if you were correct
now let's try balancing
the nitrogen first we have two nitrogens on one side the equation
only one nitrogen in the reactant side by putting a two coefficients in front
of the reactant we actually have two
two nitrogens that are balanced now let's look at the iodine
we have six iodine on the the reactant side but only two on the product
by putting up three in front of the iodine
we have a balanced equation now before moving on to this equation
always be sure to check your work everything should be balanced
two nitrogens two nitrogens 6 iodine
6 iodine the balanced equation