Answer:
Step-by-step explanation:
Rather than doing all the reactions, let's look at one in detail and develop a process for answering the rest.
Start with a pencil and paper. Pencil, because balancing equations requires some initial guesses that often need to be changed (erased).
Make a table such as shown on the attached worksheet. The first problem is demonstated on the attachment.
1. N2O5 -> N2O4 + O2
2N2O5 -> 2N2O4 + 1O2
2. KNO3 -> KNO2 + O2
We only need 1 K and 1 N for the producrs, and 1 KNO3 supplies that number. But 1 KNO3 has 3 O atoms, while the only place for the O atoms to go is )2, a diatomic molecule. To obtain 2O for the 1O2, we need to change the KNO3 coefficient to 2:
2KNO3 -> KNO2 + O2
Now change the KNO2 coefficient to 2 (to accomodate the 2 K and 2 N atoms):
2KNO3 -> 2KNO2 + O2
The reactants have 6 O atoms, so we should be balanced:
2KNO3 -> 2KNO2 + O2
K 2 2
N 2 2
O 6 4+2 = 6
3. NH4NO2 -> N2 + H2O
NH4NO2 -> N2 + 2H2O
N 2 2 0
H 4 0 4
O 2 0 2 Everything is balanced
4. O3 -> O2
O3 -> O2
2O3 -> 3O2
6 O 6 O
5. Zn + AgCl -> ZnCl2 + Ag
Zn + 2AgCl -> ZnCl2 + 2Ag
Zn 1 1
Ag 2 2
Cl 2 2
Everything is balanced.
6. 2NaOH + H2SO4 -> Na2SO4 + 2H2O
Na 2 0 2 0
O 2 4 4 2
H 2 2 4
S 1 1