Wednesday, May 2, 2012

Carbon Compounds - Alcohol (Structured)

Diagram 6 shows a flow chart of reactions involving ethanol, C2H5OH.
Based on the information in Diagram 6,
(a) State the general formula for the homologous series of ethanol. [1 mark]

(b) Oxidation of ethanol produces compound P.
(i) Name compound P [1 mark]

(ii) Describe one chemical test for compound P [2 mark]

(iii) Compound P reacts with substance Q in Reaction I to produce sodiun ethanoate and water. What is substance Q? [1 mark]

(c) The reaction between compound P and propanol produces propyl ethanoate in process II,
(i) Name process n. [1 mark]

(ii) State two physical properties of propyl ethanoate. [2 mark]

(iii) Draw a structural formula of propyl ethanoate. [1 mark]

(d) Explain the uses of ethanol in our daily life based on its physical properties. [1 mark]

[Perak Trial, Paper 2, 2011]


Carbon Compounds - Alkene (Structured)

Diagram 5 shows the flow chart of a series of reactions undergo by butene

(a) The molecular formula of butene is C4H8. State the meaning of molecular formula ? [1 mark]

(b) Butene is burnt completely in air to produce substance S and carbon dioxide gas. [1 mark]
(i) Complete the chemical equation below for the combustion reaction. [1 mark]
C4H8 + ....... O2 --> 4CO2 + ................

(ii) How many moles of substance S will be produced if 0.2 mol of butene is used in the reaction? [1 mark]

(c) Butene undergo hydration reaction to form substance P.
(i) Draw the structural formula of substance P[1 mark]

(ii) Substance P can undergo dehydration to form butene again.  Draw a labeled apparatus set- up for this dehydration reaction.[2 mark]

(d) (i) Name another chemical substance that can be used to replace acidified potassium manganate(VII) solution in Process I . [1 mark]

(ii) State one physical property of substance Q. [1 mark]

(e) Based on Process II,
(i) name substance R. [1 mark]

(ii) what would be observed when substance R is added to water? [1 mark]
[Kedah, Paper 2, 2011]

Answer: