• St. Joseph's College, Hong Kong

• CHEM 001

Ionic Bond Introduction: There are three types of chemical bonds:  Ionic bond (metallic atoms combine with non-metallic atoms)  Covalent bond (non-metallic atoms combine with non-metallic atoms)  Metallic bond (combine metallic atoms together) Part A: Electrolytes Electrolytes are compounds which conduct electricity in molten state or aqueous solution. They are decomposed by electricity during conduction (chemical change or physical change?), e.g. sodium chloride and lead(II) bromide. Compounds made up of metals and non-metals are electrolytes as they produce mobile ions in aqueous or molten states. A-1: Evidence of ions by electrolysis Question 1: Refer to the setup on the right, the observations provide evidence for the existence of ions (a) Write a word equation for the reaction in the diagram. _________________________________________________________________ _________________________________________________________________ (b) Suggest the expected observations at the positive and negative electrode when electricity is passed through the molten lead(II) bromide. _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ (c) Explain why lead(II) bromide is heated? _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ A-1: Evidence of ions by migration of coloured ions Refer to the setup on the right, the region at cathode slowly becomes blue due to the migration of positive copper(II) ions towards the negative cathode The region at anode slowly becomes orange due to the migration of negative dichromate ions towards the positive anode This study source was downloaded by 100000874968972 from CourseHero.com on 04-09-2024 08:47:29 GMT -05:00 https://www.coursehero.com/file/30596167/S3-Chem-Notes-05-Ionic-Bondpdf/ SJC/S.3Chemistry/Ionic Bond (Unit 7) 2 Question 2 (Migration of ions): A student used the following set-up to study the movement of ions. The student placed a drop of copper(II) sulphate solutio