1. Identify the atomic masses:
* Sodium (Na): 22.99 g/mol
* Chlorine (Cl): 35.45 g/mol
* Oxygen (O): 16.00 g/mol
2. Multiply the atomic mass of each element by its subscript in the formula:
* Sodium: 22.99 g/mol * 1 = 22.99 g/mol
* Chlorine: 35.45 g/mol * 1 = 35.45 g/mol
* Oxygen: 16.00 g/mol * 2 = 32.00 g/mol
3. Add the results together:
* 22.99 g/mol + 35.45 g/mol + 32.00 g/mol = 90.44 g/mol
Therefore, the formula mass of sodium chlorite (NaClO₂) is 90.44 g/mol to 2 decimal places.
