Calculate the molar mass of caffeine – C8H10N4O2
The Correct Answer and Explanation is :
To calculate the molar mass of caffeine (C₈H₁₀N₄O₂), we need to sum the atomic masses of all the elements present in the compound. The formula for caffeine is C₈H₁₀N₄O₂, meaning it consists of:
- 8 carbon (C) atoms,
- 10 hydrogen (H) atoms,
- 4 nitrogen (N) atoms,
- 2 oxygen (O) atoms.
Now, let’s look up the atomic masses of each element:
- Carbon (C) has an atomic mass of approximately 12.01 g/mol,
- Hydrogen (H) has an atomic mass of approximately 1.008 g/mol,
- Nitrogen (N) has an atomic mass of approximately 14.01 g/mol,
- Oxygen (O) has an atomic mass of approximately 16.00 g/mol.
Step 1: Multiply the atomic masses by the number of atoms for each element.
- Carbon: ( 8 \, \text{atoms} \times 12.01 \, \text{g/mol} = 96.08 \, \text{g/mol} )
- Hydrogen: ( 10 \, \text{atoms} \times 1.008 \, \text{g/mol} = 10.08 \, \text{g/mol} )
- Nitrogen: ( 4 \, \text{atoms} \times 14.01 \, \text{g/mol} = 56.04 \, \text{g/mol} )
- Oxygen: ( 2 \, \text{atoms} \times 16.00 \, \text{g/mol} = 32.00 \, \text{g/mol} )
Step 2: Add the masses together.
[
96.08 \, \text{g/mol} + 10.08 \, \text{g/mol} + 56.04 \, \text{g/mol} + 32.00 \, \text{g/mol} = 194.20 \, \text{g/mol}
]
Conclusion:
The molar mass of caffeine (C₈H₁₀N₄O₂) is 194.20 g/mol.
Explanation:
The molar mass of a substance is the mass of one mole of its molecules. To find it, we use the atomic masses of the elements that make up the compound. Each element’s atomic mass tells us how much one mole of that element weighs in grams. When calculating the molar mass of caffeine, we multiply the number of atoms of each element in the formula by its atomic mass and then sum the results. The molar mass of caffeine is critical in various scientific fields, including chemistry, pharmacology, and biochemistry, because it helps determine the quantity of substance needed for reactions or dosages in medical treatments.