2 H2O2(l) → 2 H2O(l) + O2(g)

Explanation:

In the unbalanced equation, we have:

Reactants: 2 H2O2(l)

Product: 2 H2O(l)

To balance the equation, we need to add coefficients to the reactants and products to ensure that the number of atoms of each element is the same on both sides of the equation.

Step 1: Balance Hydrogen (H) atoms:

On the reactants' side, we have 4 H atoms from 2 H2O2 molecules. On the products' side, we have 4 H atoms from 2 H2O molecules. The equation is already balanced with respect to H atoms.

Step 2: Balance Oxygen (O) atoms:

On the reactants' side, we have 4 O atoms from 2 H2O2 molecules. On the products' side, we have 2 O atoms from 2 H2O molecules and 2 O atoms from the O2 molecule. We can balance O atoms by adding a coefficient of 2 in front of H2O2.

Balanced equation:

2 H2O2(l) → 2 H2O(l) + O2(g)

Now, the equation is balanced, with 4 H atoms and 6 O atoms on both sides.