Ordinary table sugar is primarily sucrose, which has the chemical formula c12h22o11. calculate the mass percentages of carbon, hydrogen, and oxygen in sucrose.

carbon = 42.1% hydrogen = 6.5% oxygen = 51.4% First lookup the molar mass of carbon, hydrogen, and oxygen. mass of carbon = 12.0107 mass of hydrogen = 1.00794 mass of oxygen = 15.999 Now calculate the molar mass of each element in sucrose multiplying the atomic weight of each element by the number of times the element is used. carbon = 12 * 12.0107 = 144.1284 hydrogen = 22 * 1.00794 = 22.17468 oxygen = 11 * 15.999 = 175.989 Calculate the molar mass of sucrose by adding the mass of each element used. 144.1284 + 22.17468 + 175.989 = 342.2921 Finally, calculate the percentage by mass of each element by dividing the mass used for each element by the total mass of sucrose. carbon = 144.1284 / 342.2921 = 0.421068 = 42.1% hydrogen = 22.17468 / 342.2921 = 0.064783 = 6.5% oxygen = 175.989 / 342.2921 = 0.514149 = 51.4%