4.1. Electrolysis
A subsection of Chemistry, 0620, through 4. Electrochemistry
Listing 10 of 449 questions
Zinc is an important metal. Its uses include making alloys and the construction of dry cells . Name an alloy which contains zinc. What is the other metal in this alloy? name of alloy other metal in alloy The main ore of zinc is zinc blende, ZnS. The ore is heated in the presence of air to form zinc oxide and sulfur dioxide. Write the equation for this reaction. Give a major use of sulfur dioxide. Zinc can be obtained from zinc oxide in a two step process. Aqueous zinc sulfate is made from zinc oxide and then this solution is electrolysed with inert electrodes. The electrolysis is similar to that of copper(sulfate with inert electrodes. Name the reagent which will react with zinc oxide to form zinc sulfate. Complete the following for the electrolysis of aqueous zinc sulfate. Write the equation for the reaction at the negative electrode. Name the product at the positive electrode. The electrolyte changes from zinc sulfate to . A dry cell has a central rod, usually made of graphite. This is the positive electrode which is surrounded by the electrolyte, typically a paste of ammonium chloride and manganese(oxide, all of which are in a zinc container which is the negative electrode. electrons flow when cell produces energy wire graphite electrode zinc electrode electrolyte which is a paste of ammonium chloride and manganese(oxide Draw an arrow on the diagram to indicate the direction of electron fl ow. Suggest why the electrolyte is a paste. The following changes occur in a dry cell. For each change, decide if it is oxidation or reduction and give a reason for your choice. Zn to Zn2+ manganese(oxide to manganese(oxide
0620_w14_qp_32
THEORY
2014
Paper 3, Variant 2
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Questions Discovered
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