Empirical Formula Numericals
Practice problems of empirical & molecular formula numericals with step-by-step solutions
Key Concepts
- Empirical Formula: Simplest whole number ratio of atoms in a compound
- Molecular Formula: Actual number of atoms in a molecule (whole number multiple of empirical formula)
- Molecular formula = (Empirical formula)n where n = Molar mass/Empirical formula mass
A compound contains 40% carbon, 6.67% hydrogen, and 53.33% oxygen by mass. Determine its empirical formula.
A compound with empirical formula CH₂O has a molar mass of 180 g/mol. Find its molecular formula.
A hydrocarbon contains 85.7% carbon and 14.3% hydrogen by mass. Its molar mass is 56 g/mol. Find its molecular formula.
An oxide of nitrogen contains 30.4% nitrogen. Determine its empirical formula.
A compound with empirical formula C₂H₅ was found to have molar mass 58 g/mol. What is its molecular formula?
A sulfur oxide contains 40% sulfur by mass. Determine its empirical formula.
A compound contains 54.5% carbon, 9.1% hydrogen, and 36.4% oxygen. Its molecular mass is 88 g/mol. Find its molecular formula.
A chloride of silicon contains 83.5% chlorine. Determine its empirical formula.
An organic compound with empirical formula CH₂O has a vapor density of 30. Find its molecular formula.
A compound contains 52.2% carbon, 13.0% hydrogen, and 34.8% oxygen. Its molecular mass is 46 g/mol. Determine its molecular formula.
Advanced Practice (11-20)
A compound contains 43.7% phosphorus and 56.3% oxygen. Its vapor density is 71. Determine its molecular formula.
An organic compound contains 40% carbon, 6.67% hydrogen and the rest oxygen. Its molar mass is 60 g/mol. Find its molecular formula.
A metal oxide contains 60% metal. If the equivalent weight of metal is 12, find the empirical formula of the oxide.
A hydrocarbon contains 10.5g carbon per gram of hydrogen. Calculate its empirical formula.
A compound contains 38.8% chlorine, 61.2% oxygen. Its molecular mass is 167 g/mol. Determine its molecular formula.
A compound contains 5.9% hydrogen and 94.1% oxygen. If its molecular mass is 34 g/mol, find its molecular formula.