Grade 9-Basic Ed.

Write your name First Exercise :The first 8 questions are related.A, B, C and D are hydrocarbons that are collected in the different plates of fractional distillation column. These hydrocarbons are: C5H12; C20H42; C18H38 and C8H18 1)Identify the class of these hydrocarbons. Alkene Alkane Alkyne 2)What do the temperatures mentioned on the diagram represent? Melting point of the hydrocarbons Boiling point of the hydrocarbons Freezing point of the hydrocarbons 3) Give the molecular formula of A, B ,C and D. A:C20H42B:C18H38C:C8H18D:C5H12 A:C8H18B:C18H38C: C5H12D: C20H42 A: C5H12B: C8H18C: C18 H38D:C20H42 4) What is the least volatile hydrocarbon ? C8H18 C5H12 C20H42 5)Differentiate between cracking and fractional distillation. cracking is a physical method whereas fractional distillation is a chemical method Cracking is a chemical method whereas fractional distillation is a physical method Both are the same The cracking of a molecule of “D” can give a molecule of “C” and a molecule of a hydrocarbon CxHy according to the following equation: 6)Determine the molecular formula of CxHy. C2H4 C2H6 C3H6 7) Give the name of CxHy Ethane Ethene Propane 8)To which family of hydrocarbons does CxHy belongs to? Alkane Alkyne Alkene Second Exercise:The questions below are relatedHalomethanes are compounds used as refrigerants, solvents, anesthetics... They are obtained from the reaction of methane with halogens according to the equation:Where X2 is the formula of a halogen molecule such as Cl2 or Br2 . 1) What is the type of this reaction? Oxidation reaction Addition reaction Substitution reaction 2) Give the IUPAC names for the following compounds CH2Cl2 andCH3Br chloromethane and Bromomethane Dichloromethane and Dibromomethane Dichloromethane and Bromomethane Haloalkanes, like halomethanes are obtained from alkanes by replacing one or more of the hydrogen atoms by halogen atoms. The compound C2H4Cl2 has two isomers (I) and (II). The structural formula of isomer (I) is given. 3) Give the systematic name of the second isomer. Dichloromethane 1,2-dichloroethane 1,1-dichloromethane 4) Identify which of the two isomers (I) or (II) can be obtained by the reaction of one molecule of ethene with one molecule of chlorine Isomer (I) Isomer (II) Both 5) A students made a mistake and named alkane (A) as 2-ethylbutane.Choose the correct name of alkane (A) 3-methylbutane 2-ethylpentane 3-methylpentane