Sch2108:Organic Chemistry Question Paper
Sch2108:Organic Chemistry
Course:Bachelor Of Horticulture
Institution: Meru University Of Science And Technology question papers
Exam Year:2014
QUESTION ONE – (30 MARKS)
(a) Provide IUPAC name for each of the following organic compounds.
NO2
Br
CH3 CH2 CH CH2 CH2 CH3
CH2 CH3
(ii)
(iii)
(1 Mark)
(1 Mark)
(i)
(1 Mark)
2
CH3 CH2 CH CH2 OH
CH3
(v)
(iv)
(1 Mark)
(1 Mark)
(b) Draw structure of each of the following organic compound showing stereochemistry where appropriate: (i) 3 – methylbutanal (1 Mark) (ii) (E) – 3, 4 – dimethylpent-2-ene (2 Marks) (iii) (R) – butan-2-01 (2 Marks) (iv) Ethoxypropane (1 Mark) (v) (S) – pentan-2-amine (2 Marks)
(c) Predict the major product of each of the following reactions
HBr( ii) (1 Mark)
(i) CH3 (CH2)2 CH2 OH H2SO4(l) (1 Mark)
3
(iii) CH4 + 3Cl2 Light (1 Mark)
(iv)
OH
H
H CrO3, H3O4 acetone, 00C
(1 Mark)
(d) What do you understand by the following terms: (i) Hemolytic cleavag (1 Mark) (ii) Heterolytic cleavage (1 Mark) (iii) Resonance (1 Mark) (iv) Nucleophilic substitution (1 Mark)
(e) By use of asterisk (*) identify stereoganic centre in each of the following
CH3
OH
O
(i)
(11/2 Marks)
(ii) (1 1/2 Marks)
(f) Assign R or S configuration to each of the following molecules.
4
C
Br
H3C
H CO2H( i)
(3 Marks)
C
CH2CH3
HO
CH3 CO2H( ii) (3 Marks)
QUESTION TWO – (20 MARKS)
(a) What is the difference between optical isomers and conformers. (2 Marks) (b) Draw and name the constitutional isomers for compounds with molecular formula ??6??14 (5 Marks) (c) Identify the functions groups in the following organic molecule. (3 Marks)
H2N
OH
(d) (i) Draw and name the four main conformations of butane about ??2 - ??3 bond. (ii) Which of the conformer named in d(i) above is of the lower energy than the others? Explain. (2 Marks)
QUESTION THREE – (20 MARKS)
(a) Explain each of the following (i) Whereas molecular mass of butane is higher than that of ethanol, butane is a gas while ethanol is liquid at room temperature. (3 Marks) (ii) Compare the boiling point of n-hexane with that of 2-methylpentane. (3 Marks) (b) (i) What is hybridization? (2 Marks) (iii) Predict the geometry and hybridization of orbitals used in bonding on carbon atom in: i. Pentane (2 Marks)
5
ii. Ethene (2 Marks) iii. Ethyne (2 marks) (c) Describe each of the following type of alcohol. (i) Primary alcohol (2 Marks) (ii) Secondary alcohol (2 Marks) (iii) Tertiary alcohol (2 Marks)
QUESTION FOUR – (20 MARKS)
(a) Suggest an alcohol that could be used for the preparation of each of the following compounds and indicate how the reaction could be carried out: (i) Ethanol (2 Marks) (ii) 2 – Octanone (2 Marks) (iii) 5 – methyloctanal (2 Marks) (b) You are given samples of propanal 2-propanone and propanoic acid. Describe how you would use chemical test such as acid-base indicator and oxidizing agents to distinguish between the three compounds. (5 Marks) (c) Explain why there is a large number and variety of organic compounds. (4 Marks) (d) Which molecules among the following would display optical activity? Explain your answer. (i) ????3????????????2????3
(ii) ????3????2????????2
(iii)1 – bromo – 2 – chloropropane
(iv) 1, 2 – dichloromethane (5 Marks)
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