Science 30 January 1999 Grade 12 Diploma Examination

Use the following information to answer the next question.Four Fractions of a Crude Oil SampleFraction Flame Colour1 red–yellow2 bright yellow3 red4 blue–whiteNumerical Response04. A crude oil sample was distilled into four fractions. In an attempt to find the energyproduction of the fractions, a technician burned equal quantities of each. Thetechnician observed that the fractions burned at different temperatures.List the fractions in order from the one with the coolest burning temperature to the onewith the hottest burning temperature.Answer: _____ _____ _____ _____coolest hottest(Record your four-digit answer in the numerical-response section on the answer sheet.)20. Various fractions of natural gas, such as ethene (C 2 H 4(g) ), are produced in thepetrochemical industry. To produce the solvent used in dry cleaning, chlorine andfluorine are substituted for the hydrogens, which produces dichlorodifluoroethene.This compound poses the greatest environmental danger asA. a greenhouse gasB. an ozone-depleting compoundC. an oxygen block in red blood cellsD. a component of photochemical smog11