Answer:
.
Step-by-step explanation:
Indeed it is possible to solve this problem with system of multiple equations. This explanation will give an approach that gives the same result with less calculations.
Start by finding the most complex species in the equation and setting its coefficient to
. That species should as many elements as possible. For example, in this question,
,
, and
all contain three elements each. Nonetheless,
and
are more preferable for they contain more atoms.
For example, in case
is chosen as the most complex species. Set its coefficient to
:
.
There are two
atoms, one
atom, and four
atoms in that
. Since
also contains
and
, it is not certain how many
and
on the left-hand side in total. However, on the left-hand side,
appears only in
. Therefore, it is certain that there is only one
in the left-hand side of the equation.
In chemical reaction, atoms of an element are neither created nor destroyed. Therefore, the number of
atoms on the right-hand side should be the same as that on the left-hand side. Therefore, there should also be only one
atom on the right-hand side.
On the right-hand side,
is the only compound that contains
. Besides, each formula unit of
contains exactly one
. The only way to get exactly one
atom on the right-hand side is to set the coefficient of
to one, as well. The equation will then look like:
.
With a similar logic, on the right-hand side,
is the only species with
atoms. There would be exactly two
atoms on each side of the equation. On the left-hand side,
is the only species with
atoms. Each formula unit of
contains one
atom. Therefore, the coefficient of
should be
.
.
It is now certain that there are
(six)
atoms on the left-hand side of the equation. With a similar logic, there should also be six
atoms on the right-hand side of the equation. Four of these would come from
. The other two would come from
.
Each
molecule contains one
atom. As a result, there needs to be
(two)
molecules on the left-hand side.
Hence the equation:
.
Double-check the work by making sure that the number of
atoms is also the same on both sides of the equation.