Compound 1 + Compound 2 ----> Compound 3
+ -----> Lithium oxide (s)
Li (s) + O₂ (g) ------>
Compound 1:
The formula of the compound is Li (s), if we take a look at the periodic table the name of the compound is Lithium.
Compound 2:
Is the well known gas oxygen.
Compound 3:
We have to find the formula of the compound Lithium Oxide. The usual oxidation state of Li is +1, and of O is -2. So the oxide that they form is Li₂O.
Lithium (s) + Oxygen (g) -----> Lithium oxide (s)
Li (s) + O₂ (g) ------> Li₂O (s)
If we take a look at the six types of reactions, we can represent the synthesis reaction like:
A + B -----> AB
So our reaction is a synthesis reaction.
Li (s) + O₂ (g) ------> Li₂O (s)
Initially:
Oxygen: On the reactants side: 2 On the products side: 1
Lithium: On the reactants side: 1 On the products side: 2
First Step:
To balance the oxygen we have to change the coefficient in front of Li₂O (s).
Because we have 2 O on the left and 1 O on the right.
Li (s) + O₂ (g) ------> 2 Li₂O (s)
Now we have balanced the O, let's try to balance the Li:
Li (s) + O₂ (g) ------> 2 Li₂O (s)
Oxygen: On the reactants side: 2 On the products side: 2
Lithium: On the reactants side: 1 On the products side: 4
Second Step:
To balance the Li we have to change the coefficient in front of Li (s), since we have 1 Li on the left and 4 on the right.
4 Li (s) + O₂ (g) ------> 2 Li₂O (s)
Oxygen: On the reactants side: 2 On the products side: 2
Lithium: On the reactants side: 4 On the products side: 4
So it is balanced.
4 Li (s) + O₂ (g) ------> 2 Li₂O (s)