EXAM PRACTICE QUESTIONS ANSWERS Chapter 13 1 A chemical reaction releases 58 5 kJ into 150 g of water Assuming no heat is lost to the surroundings what is the temperature increase of the water The specific heat of water is 4 18 J g cid 113 C T cid 32 cid 39 Q gC cid 32 g 150 58 500 4 18 J J g cid 36 C 93 3 cid 32 C cid 36 2 Arrange the following substances in order of increasing boiling point Ne H2Se H2O NaClO3 3 Consider the following compounds CH3NH2 CH4 C2H6 SiH4 H2S H2S CH3NH2 CH4 C2H6 SiH4 b Which compound s would exhibit London forces a Which compound would have the highest molar heat of vaporization c Which compound s is the predominant intermolecular force dipole dipole interactions 4 How much heat is released when 40 0 g of steam at 250 cid 113 C cools and condenses to water at 30 0 cid 113 C Specific Heat of water is 4 18 J g cid 113 C Specific Heat of steam is 2 03 J g cid 113 C heat of vaporization of water is 2 260 kJ g d Which compound would boil at the lowest temperature e Which compound s would exhibit hydrogen bonding CH3NH2 CH4 J 40 0 g 2 03 J g cid 113 C 150 cid 113 C 2260 J g 40 0 g 40 0 g 4 18 J g cid 113 C 70 0 cid 113 C J 12200 J 90400 J 11700 J 114 300 J 5 What is the heat of fusion of chromium in kJ mol if 10 0 grams of solid chromium absorbs 2 82 cid 117 103 J of heat in melting at 2173 K its melting point 10 0 Cr g g mol 52 0 Cr cid 32 0 192 mol Cr cid 32 14 7 kJ mol 2 82 kJ mol 0 192 6 Arrange the following in order of increasing melting points CsCl BaCl2 Cdiamond HF H2 H2 HF CsCl BaCl2 Cdiamond 7 Arrange the following in order of increasing melting points Al2O3 MgCl2 NaF NaF Al2O3 Al2O3 Indicate the type of solid molecular ionic metallic covalent each of the following forms sulfur dioxide molecular solid Cgraphite covalent solid calcium bromide ionic solid lithium metallic solid methane CH4 molecular solid The average specific heat of water is 4 18 J g cid 219 cid 38 cid 17 If 905 J is added to 75 g of water at 23 9 cid 219 cid 38 cid 15 cid 3 what is the final temperature of the water sample T cid 32 cid 39 cid 32 Q gC J 905 4 18 g 75 J g cid 36 C C 2 9 cid 32 cid 36 23 9 cid 219 cid 38 2 9 cid 219 cid 38 26 8 cid 219 cid 38 Since heated is added to the water the initial temperature will increase 8 9 10 What is the predominate intermolecular force between the following pairs of molecules in solution Draw Lewis structures of each molecule Use a dashed line to represent the type of intermolecular force between the molecules Use cid 71 and cid 71 symbols to show the direction of polarity within bonds A LiCl and H2O ion dipole cid 71 H cid 71 O cid 71 O H cid 71 cid 71 H cid 71 O cid 71 H Li Cl cid 71 H cid 71 O cid 71 H cid 71 H O cid 71 H cid 71 H cid 71 H cid 71 cid 71 O H cid 71 cid 71 H B BeCl2 and C2H6 London forces cid 71 Cl cid 71 cid 71 Be Cl H H H cid 71 H H C cid 71 C H C CH3COCH3 and HF hydrogen bonding cid 71 F cid 71 H or cid 71 O cid 71 C H H C H C H H H cid 71 Cl cid 71 cid 71 Be Cl H H H cid 71 C C cid 71 H H H D AsF3 and CHCl3 dipole dipole interactions F F cid 71 As F cid 71 cid 71 Cl cid 71 C or F F cid 71 As F cid 71 cid 71 Cl cid 71 C H Cl Cl H Cl Cl