CHM1204(F)/Page 1 of 9 INTI INTERNATIONAL UNIVERSITY FOUNDATION IN SCIENCE (CFSI) CHM1204: CHEMISTRY 2 FINAL EXAMINATION: JANUARY 2013 SESSION Instructions: This paper consists of FIVE (5) questions. Answer any FOUR (4) questions in the answer booklet provided. All questions carry equal marks. Question 1 Draw the structural formula for each of the following compounds: (iv) (v) trans- 1,3- dibromocyclopentane 2- ethyl-7-methyl-4-octyne 3-methylcyclohexanol Acetaldehyde Sodium propanoate A mixture of cyclohexane and bromine in an inert solvent is exposed to ultraviolet light. The bromine water is gradually decolorized and colourless fumes are produced. Draw the expanded structural formula of cyclohexane. Write the equations for the reactions that occur. Name the chemical reactions occurred above.
CHM 1204 (F)/ Page 2 of 9 (c) Draw the structures of the aldehydes or ketones formed by the oxidation of the compounds given below:- The structure of amino acid glycine is as shown below: Draw the structure of zwitterion formed by glycine. Draw the structural form of glycine that predominates at the following ph:- ph 2.00 ph 10.00 One of the denaturing agents for protein is ph. Explain what happen to the protein at isoelectric point.
CHM 1204 (F)/ Page 3 of 9 Question 2 Draw the structures of the products form when propene reacts with each of the following substances by an addition reaction. Assume that needs of catalyst or other conditions are provided. H 2 Br 2 (iv) HBr H 2 O (in acid) Draw the structural formula for all the possible products for each of the chemical reactions below. If no reaction occurs, write no reaction. (c) C 6 H 14 has structural isomers. Deduce the number of structural isomers for C 6 H 14.
CHM 1204 (F)/ Page 4 of 9 The structure shown below is a galactose compound:- Classify the galactose above as a D isomer or an L isomer. Indicate the chiral centres in the molecule of galactose with an asterisk (*). You may re-draw the above structure onto your answer sheet and indicate all the chiral carbons. Identify the type of stereoisomerism galactose molecule above exhibits. (iv) (v) Galactose is a monosaccharide compound. Classify this monosaccharide according to both the number of carbon atoms and the type of carbonyl group present. Represent the galactose above using Haworth projection. You may ignore its anomeric.
CHM 1204 (F)/ Page 5 of 9 Question 3 Alcohol B has esters which are responsible for the flavors of various fruits and has the molecular formula of C 5 H 12 O. Reaction of B with acidified potassium dichromate (VI) produces a compound C, C 5 H 10 O 2. Heating B over Al 2 O 3 produces D, C 5 H 10. Vigorous oxidation of D forms 2-methylpropanoic acid as one of the products. Draw and name the expanded structures for B, C and D. (6 marks) Alkanes are hydrocarbon compounds that used as fuels. A student burned some heptanes in air and found that the combustion was incomplete. Write an equation for the incomplete combustion of heptane to produce carbon monoxide as the only carbon-containing product. Give one reason why the combustion was incomplete. (c) Arrange the following compounds on the basis of increasing boiling point: Heptanoic acid, 3-heptanone, 5-heptanol, 3-heptene, 4-heptanamine The structure shown below is an oleic acid. It can react with glycerol to form triacylglycerol. COOH Classify the type of designation (SFA, MUFA, OR PUFA) for oleic acid. Assign the shorthand designation for this oleic acid on the basis of carbon chain length and the degree of unsaturation. Draw the structural formula of the triacylglycerol produced from the reaction between glycerol and three molecules of oleic acid.
CHM 1204 (F)/ Page 6 of 9 (iv) Draw the structural formula of the organic products formed when triacylglycerol undergoes the reactions below: Complete hydrolysis (e) Complete saponification using NaOH Draw the structural formula of the amino acids formed from the following hydrolysis reaction. + H 2 O H + heat (3 marks) (f) The acid strength of ethanol and ethanoic acid is determined by pka value. Ethanoic acid (pka = 4.76) has lower pka value compared to ethanol (pka = 16.0). Explain your reasoning in terms of resonance effect. (3 marks) Question 4 Draw the structural formula for each of the following compounds. 3,3- dimethylcyclopentanone Cyclopentylbenzoate Ethanoic anhydride Draw the structural formula and assign the IUPAC name for all the reagents needed to form each compounds in the following. (4 marks)
CHM 1204 (F)/ Page 7 of 9 + NaOH (4 marks) (c) The effect of substrate concentrations played an important role in determining the rate of reaction. Draw a graph that describes the effect of increasing the concentration of substrate to the rate of reaction in: un-catalyzed reaction. Doubling the substrate concentrations An increase in temperature will increase the rate of reaction if a non-enzymatic catalyst is used. However, an increase in temperature will eventually decrease the rate of reaction when enzyme catalyst is used. Explain the apparent contradiction of these two statements. The mitochondria are aerobic cell organelles that are responsible for most of the ATP production in eukaryotic cells. ATP is produced by two pathways which is the glycolysis and complete oxidation process. Compare the number of molecules of ATP produced by glycolysis to the number of ATP produced by oxidation of glucose by aerobic respiration. Which pathway produces more ATP? Explain your reasoning. (3 marks)
CHM 1204 (F)/ Page 8 of 9 Question 5 The boiling points of butanol and butanal are 117.7 C and 74.8 C respectively. Explain why the alcohol compound has a higher boiling point than the carbonyl compound. (4 marks) Give the IUPAC names for each of the following compounds. (c) Benzaldehyde is mostly found in nuts. This compound can be produced from alcohol. Draw the structural formula of the alcohol and classify as primary, secondary or tertiary alcohol. (3 marks) Write the oxidation equation for the formation of benzaldehyde. Provide all the reagents and condition needed. (4 marks) (e) List TWO differences between DNA and RNA. If a gene had the nucleotide sequence 5 TAC GGG CAT AGG CCT TAA AGC TAG CTT 3 Write the sequence of the mrna.
CHM 1204 (F)/ Page 9 of 9 (f) From the DNA base sequence, section Ф are exons, and sections are introns. 5 GGC-TAT- AGT-AGC- CCC 3 (Ф) ( ) (Ф) ( ) (Ф) Write the complementary strand to the single DNA strand shown above. Determine the base sequence in hnrna synthesized from the complementary DNA template strand above. What is the structure of mrna obtained by splicing the hnrna? --THE END-- CHM1204(F)/JAN2013/NSM/110313