Calculate the molecular mass of menthol, C10H20. 156.26 amu
The Correct Answer and Explanation is:
Correct Answer: 156.26 amu
Explanation:
To calculate the molecular mass of a compound, you must sum the atomic masses of all the atoms present in its chemical formula. The molecular mass represents the total mass of one molecule of the substance and is expressed in atomic mass units (amu).
The chemical formula for menthol is given as C₁₀H₂₀O. Let’s break down the calculation step-by-step:
1. Identify the Elements and Atom Count:
First, we identify the elements and the number of atoms for each from the chemical formula C₁₀H₂₀O:
- Carbon (C): There are 10 atoms.
- Hydrogen (H): There are 20 atoms.
- Oxygen (O): There is 1 atom.
2. Find the Atomic Mass of Each Element:
Next, we use the standard average atomic masses for each element as found on the periodic table:
- The atomic mass of Carbon (C) is approximately 12.01 amu.
- The atomic mass of Hydrogen (H) is approximately 1.008 amu.
- The atomic mass of Oxygen (O) is approximately 16.00 amu.
3. Calculate the Total Mass for Each Element:
Now, we multiply the number of atoms of each element by its atomic mass to find its total contribution to the molecule’s overall mass.
- Total mass from Carbon: 10 atoms × 12.01 amu/atom = 120.10 amu
- Total mass from Hydrogen: 20 atoms × 1.008 amu/atom = 20.16 amu
- Total mass from Oxygen: 1 atom × 16.00 amu/atom = 16.00 amu
4. Sum the Masses to Find the Molecular Mass:
Finally, we add the total masses of all the elements together to determine the molecular mass of menthol.
- Molecular Mass = (Total mass of Carbon) + (Total mass of Hydrogen) + (Total mass of Oxygen)
- Molecular Mass = 120.10 amu + 20.16 amu + 16.00 amu
- Molecular Mass = 156.26 amu
This calculated value matches one of the options provided. Therefore, the molecular mass of menthol is 156.26 amu
