To calculate the molar mass of Vitamin D, we need to find the atomic mass of each element in the compound and add them up. Based on the information provided, Vitamin D has two oxygen atoms per formula unit, so the molecular formula can be represented as CxHyO2.
The atomic mass of Carbon (C) is 12, Hydrogen (H) is 1, and Oxygen (O) is 16.
Given that Vitamin D is 4.03% oxygen by mass, we can calculate the number of moles of oxygen in 100g of Vitamin D:
(4.03g O / 100g Vitamin D) / (16g O / 1 mole O) = 0.25 moles O
Since each molecule of Vitamin D has 2 oxygen atoms, there are 0.25 x 2 = 0.5 moles of Vitamin D in 100g.
So, the molar mass of Vitamin D can be calculated as follows:
12g C / 1 mole C + 1g H / 1 mole H + 16g O / 1 mole O = (12 + 1 + 32) g / 0.5 moles = 45 g/mol
Therefore, the molar mass of Vitamin D is 45 g/mol.