Answer:
1 Ca(OH)2 + 1 (NH4)2SO4 ---> 1 CaSO4 + 2 NH3 + 2 H2O
Step-by-step explanation:
The photo I attached should make more sense as an explanation.
When balancing equations, the first and most important step is to count the # of each type of element on each side.
In this problem there are 5: Ca, O, H, N, and S.
Once you do that you can begin balancing.
Here is the initial tally for the elements in this problem:
On the left.....
Ca - 1
N - 2
S - 1
O - 6
H - 10
On the right.....
Ca - 1
N - 1
S - 1
O - 5
H - 5
Looking at these values, we can see N, O, and H all need adjusting the right side. You should never start balancing with O or H unless they are the only elements that need adjusting. They usually balance out with the rest of your work or with water in the end.
So given all of that, you should start balancing with N on the right. Giving NH3 a coefficient of 2 will change the number of Nitrogen atoms on the right to 2. Be careful though! It will also change the number of Hydrogen atoms from 5 to 8 (because (2*3) =6 and 6+2 =8).
Let's tally our numbers again.
On the left..... (these should be unchanged)
Ca - 1
N - 2
S - 1
O - 6
H - 10
On the right.....
Ca - 1
N - 2
S - 1
O - 5
H - 8
Okay, now we see only O and H need adjusting on the right. Luckily there is H2O so we can do that without impacting the number of other atoms.
Give H2O a coefficient of 2 and count the number of atoms on the right again.
On the right.....
Ca - 1
N - 2
S - 1
O - 6 (because 4 from CaSO4 plus 2 from 2H2O = 6)
H - 10 (6 from NH3 plus 4 from 2H2O = 10)
Do these numbers match what you have on the the left side of the equation? Yes! It is balanced so you do not need to adjust anymore. Your coefficients in the answer will be 1-1-1-2-2.