Empirical and Molecular Formula Worksheet
A Grade 11 Chemistry worksheet covering empirical and molecular formulas, including calculations and definitions.
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Empirical and Molecular Formula Worksheet
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Read each question carefully and provide your answers in the space provided. Show all your work for calculation questions.
1. Which of the following statements best describes an empirical formula?
It shows the actual number of atoms of each element in a molecule.
It represents the simplest whole-number ratio of atoms in a compound.
It indicates the arrangement of atoms in a molecule.
It is used for ionic compounds only.
2. Which of the following compounds has the same empirical formula as C6H12O6?
CH3COOH
C12H22O11
CH2O
C2H6O
3. The molecular formula is always a whole-number multiple of the formula.
4. To determine the empirical formula from percent composition, you first assume a gram sample.
5. A compound is found to contain 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. Determine its empirical formula. (Atomic masses: C=12.01, H=1.01, O=16.00)
6. If the molar mass of the compound in question 5 is 180.18 g/mol, what is its molecular formula?
7. The empirical formula of a compound can sometimes be the same as its molecular formula.
True
False
8. All ionic compounds have molecular formulas that are different from their empirical formulas.
True
False
Match the term with its definition.
9. Molecular formula
a. The simplest whole-number ratio of atoms in a compound.
10. Empirical formula
b. The actual number of atoms of each element in a molecule.
11. A compound contains 85.6% carbon and 14.4% hydrogen. Its molar mass is 42.08 g/mol. Determine both the empirical and molecular formulas of the compound. (Atomic masses: C=12.01, H=1.01)