Chemistry Past Questions and Answers

(a)(i) What is the general formula for alkanoic acids?<br/>(ii) State two chemical properties of ethanoic acid.<br/>(b) Which of propene, butane and pentane<br/>(i) will decolorize acidified KMnO\(_4\) solution?<br/>(ii) can be easily polymerized?<br/>(iii) is an isomer of methylpropane?<br/>(iv) can be obtained from an alkanol by dehydration?

(a)(i) What is meant by the activation energy of a reaction?<br/>(ii) State the effect of a catalyst on activation energy.<br/> <br/>(b) What substance serves as a catalyst in each of the following?<br/>(I) Hydrogenation of oils<br/>(ii) Biochemical reactions.

(a) Write an equation for the reaction of chlorine with<br/>(i) potassium iodide solution;<br/>(ii) zinc on heating<br/>(b) Identify the product Q in the following reaction: Cl\(_2\) + 2NaOH \(\to\) NaCl + H\(_2\)O + Q.

(a) List two uses of sodium trioxocarbonate (IV).<br/>(b) Sodium trioxocarbonate (IV) solution is alkaline.<br/>(i) What phenomenon is responsible for this observation?<br/>(ii) Name the product obtained on passing carbon (IV) oxide into saturated sodium trioxocarbonate (IV) solution.

Xg of a pure sample of iron (II) sulphide reacted completely with excess dilute hydrochloric acid to give 3.20g of iron (II) chloride according to the following equation: FeS\(_{(s)}\) + 2HCI\(_{(aq)}\) ---> FeCl\(_{2(aq)}\) + H\(_2\)S\(_{(g)}\).<br/>(a) Mention one method apart from heating by which the reaction can be made to proceed faster<br/>(b) Calculate the value of X. [CI = 35.5, Fe = 56; FeS = 88g mol\(^{-1}\)]