Chemistry Past Questions and Answers

(a)(i) State three characteristics of a homologous series.<br/>(ii) Give the name and structural formula of the second member of the alkyne series.<br/>(iii) Write an equation to represent the combustion of ethane in excess oxygen.<br/> <br/>(b) Name the type of reaction involved in the conversion of ethanol to<br/>(i) ethene;<br/>(ii) ethylethanoate;<br/>(iii) chloroethane;<br/>(iv) ethoxide<br/>(v) ethanoic acid<br/> <br/>(c) Consider the following compound.<br/><br/>(i) Write its IUPAC name.<br/>(ii) Give its molecular formula and empirical formula<br/>(iii) List the products of its H H 0 reaction with saturated Na\(_2\)CO\(_3\) solution.<br/>(iv) State with reason whether its boiling point will be higher or lower than that of the corresponding alkane.<br/> <br/>(d) A vegetable oil X was treated with activated charcoal and then with a gas Y in the presence of a catalyst in order to manufacture<br/>(i) Identify Y.<br/>(ii) State the function of the activated charcoal.<br/>(iii) What is the catalyst used?<br/>(iv) If a sample of X is heated with concentrated sodium hydroxide solution, list the products that will be obtained.

(a) List two substances that can be used in the laboratory to<br/>(i) dry hydrogen;<br/>(ii) remove carbon (IV) oxide from a sample of air;<br/>(iii) convert hot copper (II) oxide to copper;<br/>(iv) prepare zinc chloride by the action of dilute HCI.<br/> <br/>(b)(i) Name two alloys which contain lead.<br/>(ii) State and explain what is observed on bubbling H\(_2\)S into a solution of Pb(NO)\(_2\).<br/>(iii) A metal M exists as a silvery white solid at temperatures above 18°C and as a grey solid below 18°C.<br/>I. name the phenomenon exhibited by M.<br/>II. What term is used to describe the temperature given as 18°C in this case?<br/> <br/>(c)(i) Write an equation for the action of heat on each of the following compounds:<br/>I. AgNO\(_3\)<br/>II. (NH4)\(_2\)CO\(_3\).<br/> <br/>(ii) Copy and complete the table below<br/><table class='tbn'><tbody><tr><td> Metal </td><td> Name of main ore </td><td> Method of extraction </td><td> One major use Haematite </td></tr><tr><td> – </td><td> Haematite </td><td> – </td><td> – </td></tr><tr><td> – </td><td> – </td><td> Electrolysis of molten oxide </td><td> – </td></tr></tbody></table><br/><br/><br/><br/>

If the relative molecular mass of an element is not a whole number, it can be deduced that the element is

The atomic number of chlorine is 17. What is the number of electrons in a chloride ion?

Consider the following equation; Cr<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>7(aq)</sub><sup style='font-size: smaller;'>2-</sup> + 14H<sup style='font-size: smaller;'>+</sup><sub style='font-size: smaller;'>(aq)</sub> + 6e<sup style='font-size: smaller;'>-</sup> → 2Cr<sup style='font-size: smaller;'>3+</sup><sub style='font-size: smaller;'>(aq)</sub> + 7H<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>(I)</sub>. The oxidation number of chromium changes from