If 60 g of M combines with 24 g of oxygen, what would the empirical formula of the oxide be? ( molar mass of M = 120, O = 16)

Step 1: Analyze the question We are given the masses of M and oxygen in an oxide, and we need the simplest whole-number ratio of atoms (the empirical formula).

Step 2: Concept Empirical formula steps:

1. Find moles of each element (mass ÷ molar mass)
2. Divide by the smallest number of moles
3. Convert to whole numbers

Step 3: Solution

• Moles of M = 60 ÷ 120 = 0.5 mol
• Moles of O = 24 ÷ 16 = 1.5 mol

Divide by the smallest (0.5):

• M = 0.5 ÷ 0.5 = 1
• O = 1.5 ÷ 0.5 = 3

The ratio M : O = 1 : 3, so the empirical formula is MO₃.

Step 4: Answer

Tip: Remember "Mass → Moles → Divide → Whole number". If the ratio gives a decimal like 1.5, multiply everything by 2. Here the numbers divide out cleanly, so no extra step is needed.