Homework Sourse3 Vanillin is the main component of vanilla flavorings It pe
3. Vanillin is the main component of vanilla flavorings. It percentage composition is 63.2% carbon, 5.26% hydrogen, and 31.6% oxygen. What is its empirical formula? The empirical formula of p-xylene is C4Hs; the molar mass of p-xylene is 106g/mole. What is the molecular formula for p-xylene? What is the total number of atoms present in a 20.00g sample of this substance? The plastic pipe used for most of the water and sewer lines is made of a polymer called PVC. The compound used to synthesize PVC has a general formula CxHyE This substance is composed of 38.4% C and 4.8% H. What is the identity of element E? What is the empirical formula of this compound? 4. 5.
Solution
3.
Element Mass Number of moles Division by small number Nearest whole number
C 63.2 63.2 / 12 = 5.27 5.27 / 1.975 = 2.67 2.67 * 3 = 8.00
H 5.26 5.26 / 1 = 5.26 5.26 / 1.975 = 2.67 2.67 * 3 = 8.00
O 31.6 31.6 / 16 = 1.975 1.975 / 1.975 = 1 1 * 3 = 3.00
Therefore,
Emperical formula = C8H8O3
