The carbohydrate fructose found in honey and fruits has an empirical formula ofCH2O
. If the experimental molar mass of fructose is 180g
, what is its molecular formula?
The Correct Answer and Explanation is:
The empirical formula of fructose is CH2OCH_2OCH2O, which means that the ratio of carbon, hydrogen, and oxygen atoms in the simplest form is 1:2:1. The next step is to determine the molecular formula, which tells us how many of each type of atom are in a single molecule of fructose.
Step-by-Step Solution:
- Calculate the molar mass of the empirical formula:
The empirical formula for fructose is CH2OCH_2OCH2O, so the molar mass of one molecule of CH2OCH_2OCH2O is:- Carbon (C) has an atomic mass of 12.01 g/mol.
- Hydrogen (H) has an atomic mass of 1.008 g/mol.
- Oxygen (O) has an atomic mass of 16.00 g/mol.
- Divide the experimental molar mass by the empirical formula mass:
The experimental molar mass of fructose is given as 180 g/mol. To find how many times the empirical formula fits into the molecular formula, divide the molar mass of fructose by the empirical formula’s molar mass: 18030.03≈6\frac{180}{30.03} \approx 630.03180≈6 - Determine the molecular formula:
Since the empirical formula mass is 30.03 g/mol, and the ratio is 6, we multiply the empirical formula by 6 to find the molecular formula: (CH2O)6=C6H12O6(CH_2O)_6 = C_6H_{12}O_6(CH2O)6=C6H12O6 So, the molecular formula of fructose is C6H12O6C_6H_{12}O_6C6H12O6.
Conclusion:
The molecular formula of fructose is C6H12O6C_6H_{12}O_6C6H12O6. This shows that fructose is composed of 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms in each molecule, and it is commonly referred to as a simple sugar or monosaccharide. The empirical formula CH2OCH_2OCH2O represents the simplest ratio of the elements, while the molecular formula C6H12O6C_6H_{12}O_6C6H12O6 describes the actual number of atoms in a molecule of fructose.
