b The molar mass of menthol is 156.26 g mol Find the molecular formula of menthol marks)
The Correct Answer and Explanation is:
To determine the molecular formula of menthol, we first need to know the chemical composition of menthol, which consists of carbon (C), hydrogen (H), and oxygen (O) atoms. The molecular formula is determined based on the empirical formula and molar mass.
Step 1: Empirical Formula of Menthol
The molecular structure of menthol contains:
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
The empirical formula for menthol is C10H20OC_10H_{20}OC10H20O, as it consists of 10 carbon atoms, 20 hydrogen atoms, and one oxygen atom.
Step 2: Molar Mass of the Empirical Formula
Next, let’s calculate the molar mass of the empirical formula:
- The molar mass of carbon (C) is 12.01 g/mol.
- The molar mass of hydrogen (H) is 1.008 g/mol.
- The molar mass of oxygen (O) is 16.00 g/mol.
So, for C10H20OC_{10}H_{20}OC10H20O:Molar mass=(10×12.01)+(20×1.008)+(1×16.00)\text{Molar mass} = (10 \times 12.01) + (20 \times 1.008) + (1 \times 16.00)Molar mass=(10×12.01)+(20×1.008)+(1×16.00)=120.1+20.16+16.00=156.26 g/mol= 120.1 + 20.16 + 16.00 = 156.26 \, \text{g/mol}=120.1+20.16+16.00=156.26g/mol
Step 3: Compare the Molar Mass
The molar mass of menthol is given as 156.26 g/mol, which matches the calculated molar mass of the empirical formula C10H20OC_{10}H_{20}OC10H20O. Therefore, the empirical formula is also the molecular formula.
Conclusion
The molecular formula of menthol is C10H20OC_{10}H_{20}OC10H20O, and this is derived by comparing the molar mass of the compound with that of the empirical formula.
