Example:Calculate the Unsaturations for a Compound with Formula CsHa. Calculate the number of hydrogen atoms for a saturated compound with five carbons: (2XC)+2 (2×5)+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 22 The compound has two unsaturations.They can be two double bonds,two rings,one double bond and one ring, or 1 triple bond. 9 2013 Pearson Education Inc.Example: Calculate the Unsaturations for a Compound with Formula C5H8. • 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, one double bond and one ring, or 1 triple bond. 9 © 2013 Pearson Education Inc