Question

How can I balance lithium+oxygen----+ lithium oxide?

Answer 1

Hint: A chemical equation is the chemical formula that provides the information of the elements and molecules that are reacting as well as the molecules that are being produced from that reaction.

Complete step by step answer:
The Law of Conservation of Mass states that the mass of the reactants must balance the mass of the products.
To balance a chemical equation, the atoms of both the elements and molecules on the reactant side (left side) and product side (right side) must be equal to each other. The chemical equation is balanced, meaning that equal numbers of atoms for each element involved in the reaction are represented on the reactant and product sides.
This is a requirement the equation must satisfy to be consistent with the law of conservation of matter.
If an element appears in more than one formula on a given side of the equation, the number of atoms represented in each must be computed and then added together.

Balancing a chemical equation means having the same number of ions / atoms as reactants as products. Start with the product; in this case Lithium Oxide (which is\[\text{L}{{\text{i}}_{\text{2}}}\text{O}\] )
Oxygen is a reactant in the form \[{{\text{O}}_{\text{2}}}\]
Therefore so far we have;
\[\text{Li}+{{\text{O}}_{2}}\to \text{L}{{\text{i}}_{\text{2}}}\text{O}\]
We have $2$ Oxygen atoms on the left side of the equation, but only \[1\] Oxygen atom on the right side. We cannot decrease the amount of oxygen on the left side as the oxygen is already in its smallest unit, therefore to get the number of oxygen atoms balanced, we need to adjust the right side.
By making $2$ lots of \[\text{L}{{\text{i}}_{\text{2}}}\text{O}\] as products, we end up with $2$ Oxygen atoms on the right side (the same number as the left side). So we now have;
\[\text{Li}+{{\text{O}}_{2}}\to 2\text{L}{{\text{i}}_{\text{2}}}\text{O}\] Now we have $4$ Lithium atoms on the right side, and only \[1\] on the left side. To rectify this, we need to have 4 Lithium atoms on the left side as well.
\[4\text{Li}+{{\text{O}}_{2}}\to 2\text{L}{{\text{i}}_{\text{2}}}\text{O}\]

Note: It may be confirmed by simply summing the numbers of atoms on either side of the arrow and comparing these sums to ensure they are equal. Note that the number of atoms for a given element is calculated by multiplying the coefficient of any formula containing that element by the element’s subscript in the formula.