Example:Calculate the Unsaturations for a Compound with Formula C5Ha. First calculate the number of hydrogen atoms for a saturated compound with five carbons: (2×C)+2 (2X5)+2=12 Now subtract from this number the actual number of hydrogen atoms in the formula and divide by 2: 12-8=4=2 unsaturations 22 The compound has two unsaturations,they can be two double bonds,two rings,or one double bond and one ring. Chapter 7 9Chapter 7 9 Example: Calculate the Unsaturations for a Compound with Formula C5H8 . • First calculate the number of hydrogen atoms for a saturated compound with five carbons: (2 x C) + 2 (2 x 5) + 2 = 12 • Now subtract from this number the actual number of hydrogen atoms in the formula and divide by 2: 12 – 8 = 4 = 2 unsaturations 2 2 • The compound has two unsaturations, they can be two double bonds, two rings, or one double bond and one ring