How do you balance #BaCl_2 + Al_2S_3 -> BaS + AlCl_3#?
Create an equation for each of the elements, then set one of them and solve for the others. Answer is:
Let the four balancing factors be
For each element, we can have a balance equation:
You can notice that if you set one of these factors it will chain you to the next factor. Let's set
Now the equation can be balanced:
However, many don't like the fractions because of the molecule concept. Since they have a common denuminator, multiply everything by 3 to get ride of the fractions: