Beatty 19.1_Alkanes WS1_2023_Answers_4E1

1 Beatty Secondary School Science Department (Chemistry Unit) Chemistry 6092 Name: ___________________________________ ( ) Date: _______________ Class: 4E1 TOPIC: ALKANES (WORKSHEET 1) Learning Objectives: (a) Describe an homologous series as a group of compounds with a general formula, similar chemical properties and showing a gradation in physical properties as a result of increase in the size and mass of the molecules, e.g. melting and bo iling points; viscosity; flammability. (b) Describe the alkanes as an homologous series of saturated hydrocarbons with the general formula CnH2n+2. (c) Draw the structures of branched and unbranched alkanes, C1 to C 4, and name the unbranched alkanes, methane to butane. (d) Describe the properties of alkanes (exemplified by methane) as being generally unreactive except in terms of burning and substitution by chlorine. Multiple-Choice Questions 1 Decane is an alkane containing ten ca rbon atoms per molecule. What is its molecular formula? A C10H18 B C10H20 C C10H22 D C10H24 ( C ) 2 The structure of compound J is shown. Which row describes J? saturated hydrocarbon A no no B no yes C yes no D yes yes ( C ) 3 Methane is the first member of the alkane homologous series. Which ro w describes the changes in flamm ability and the size of the molecules in th e alkane homologous series from methane to propane? flammability size of molecules A decreases decreases B decreases increases C increases decreases D increases increases ( B )

2 4 Which of these properties of alkanes decreases with increasing relative molecular mass of the alkane? A melting point B flammability C density D boiling point ( B ) 5 Which statement about a homologous series is correct? A The boiling point increases with decreasing relative molecular mass. B The members have the same empirical formula (formula showing the number of atoms in the simplest ratio). C The members have similar chemical properties. D The relative molecular masses of consecutive members differ by 12. ( C ) 6 Nonane is an alkane present in petrol. What are the products formed when nonane is completely burnt in air? A carbon dioxide and hydrogen B carbon monoxide and water C carbon dioxide and water D carbon dioxide, carbon monoxide and water ( C ) 7 What are the main products when chlorine reacts with methane? A chloromethane and hydrogen B chloromethane and hydrogen chloride C dichloromethane and hydrogen D trichloromethane and carbon chloride ( B ) 8 The diagrams show the structures of three compounds. Which compounds can be products of substitution reactions of ethane with chlorine? A 1 only B 2 only C 1 and 3 only D 1, 2 and 3 ( D ) 9 100 c