Organic Chemistry I Past Paper - Al-Bayan University 2023-2024 Form A PDF

College of pharmacy / Al-Bayan University June. 2024 Mid-exam in (Org. Chem. I) Lecturer: Dr. Haider Sultani 2nd semester- 1st stage. Time 1.5 hr Part I: True or False (e...

College of pharmacy / Al-Bayan University June. 2024 Mid-exam in (Org. Chem. I) Lecturer: Dr. Haider Sultani 2nd semester- 1st stage. Time 1.5 hr Part I: True or False (each question is 1 point, 10 points in total) Q1. Atomic weight of an element is equal to the number of electrons. F Q2. Electrons around the nucleus can orbit only for some time, afterwards it will give its energy and collide with the nucleus. F Q3. Electrons in shell 2, can occupy only two different type of orbitals, namely s & p orbitals. T Q4. Valance electrons are the most important since it’s responsible for chemical reactions. T Q5. The kernel of an atom corresponds to the inner electrons. F Q6. According to Gilbert Newton Lewis, atoms can reach stability only by transfer of electrons. F Q7. Coordinate bonding is just another type of chemical covalent bond, a good example is the bonding in hydrochloric acid HCl. F Q8. Ionic bonding is stronger than covalent bond, one exception is the covalent bonding in Dimond. T Q9. The chemical bond in NaI (sodium iodide) is an Ionic bond. T Q10. When tetrachloromethane (CCl4) is shaken with aqueous silver nitrate, no reaction is expected to take place. T ---------------------------------------End of part I------------------------------------------- Part II: Multiple choice questions (each question is 1 point, 15 points in total) Note: Choose the most correct choice Q1. Testosterone, is the male sex hormone that is made in the testicles, consider the structure below and select the functional groups that testosterone contains. A. Alkane B. ketone C. Alcohol D. alkene E. B+C+D Q2. Methane (CH4) is a sp3 hybridized carbon, what is true regarding Methane. A. The bond angle is about 120 degrees. B. it’s mostly used as fuel. C. One S orbital is combined with 2 p orbital D. There is no eclipsed\staggered isomer. E. B+D Q3. Menthol is a natural product, used to treat occasional minor irritation, pain, sore mouth, and sore throat as well as cough associated with a cold or inhaled irritants. What is true regarding this compound? 1 Good luck- Dr. Haider Namh Sultani  A. It’s a heterocyclic compound B. carbocyclic compound C. The carbon connected to the hydroxyl group is sp2 hybridized D. There are three tertiary carbon presents. E. B+D Q4. Consider the following compounds and select the correct statement. A. Pinene contains at least one tertiary carbon. B. There is one quaternary carbon present in pinene. C. Nicotine, represent two-heterocyclic compounds connected together. D. A+B+C E. Limonene contains 4 primary carbons. Q5. Select the right option that shows how the following structures to show how electron pairs must be moved to interconvert the structures and locate any formal charges. A. B. C. D. E. Q6. Consider the following structure and select the correct choice. A. The longest chain contains 9 carbon chain. B. The correct IUPAC name is 7-bromo-6-(sec- butyl)-3-ethyl-2,2-dimethylnonane C. 3-bromo-4-sec-butyl-7-tert-butylnonane D. A+B E. A+C 2 Good luck- Dr. Haider Namh Sultani Q7. Which of the following compounds will have the highest boiling point (van der Waals attractions)? A. 5>2>3>1>4 B. 5>1>3>2>4 C. 5>3>1>2>4 D. 3>5>2>1>4 E. 3>1>2>4>5 Q8. What is the chemical formula for the following compounds, respectively? A. C7H9, C3H5Cl2 & C4H7Br B. C7H14, C3H4Cl2 & C5H8Br C. C7H13, C3H4Cl2 & C5H7Br D. C7H16, C3H4Cl2 & C5H7Br E. C7H14, C3H4Cl2 & C5H9Br Q9. Consider cyclohexane and choice the incorrect answer. A. The bond angle in cyclohexane should be 120 degrees if its planner. B. If A was a methyl group, then the chair flip will take place to put the methyl group in position A2. C. If both A & B were a methyl group, chair formation will take place to put the methyl groups in position A2 & B2 respectively. D. Methyl group in axial position, will suffer from 1,3-diaxial interactions. E. The conformation on the left will be present in approx. 95% if either A or B are methyl groups. Q10. Select the right answer & fill in the blank regarding isomers. 3 Good luck- Dr. Haider Namh Sultani  A. 1. Isomer of hexane, 2. Stereoisomers, 3. Rotation in butane & 4. not interconvertible by bond rotation B. 1. butane, 2. Stereoisomers, 3. Rotation in methane & 4. Not interconvertible by bond rotation C. 1. Ethanol and methoxymethane 2. Stereoisomers, 3. Rotation in ethane & 4. interconvertible by bond rotation D. A+C E. None of the above Q11. Compounds containing similar functional group will have similar reactivity, divide the following compounds into groups that might be expected to exhibit similar chemical behavior. 1.C4H10 2. CH3OCH3 3. C3H7OH 4. HOCH2CH2CH2OH 5. CH3NH2 6. CH3CH2CH3 7. (CH3)2CHNH2 8. CH3CH2OCH3 A. 1&6, 2&8, 3&4, 5&7 B. 1&3, 2&8, 6&4, 5&7 C. 1&8, 2&3, 6&4, 5&7 D. 1&7, 2&8, 3&4, 5&6 E. 1&4, 2&8, 6&3, 5&7 Q12. What is the IUPAC name for the following compound? A. 3-cyclobutyl-3,4-diethylhexane B. 3,4-diethyl-3-cyclobutylhexane C. A or B D. (2,4- diethylhexan-3-yl)cyclobutene E. none of the above Q13. Name the following cis–trans pairs? A. cis-1,3-dichlorocyclohexane & cis-1,3-dichlorocyclohexane B. cis-1,3-dichlorocyclohexane & trans-1,3-dichlorocyclohexane C. trans-1,3-dichlorocyclohexane & cis-1,3-dichlorocyclohexane D. trans-1,3-dichlorocyclohexane & trans-1,3-dichlorocyclohexane E. none of the above Q14. Go back to question 13, and choice the correct answer? A. cis-1,3-dichlorocyclohexane is more stable. B. trans-1,3-dichlorocyclohexane is more stable. C. cis-1,3-dichlorocyclohexane is less stable. D. trans-1,3-dichlorocyclohexane has no 1,3-diaxial interaction. E. none of the above 4 Good luck- Dr. Haider Namh Sultani Q15. How many monobromination products can be obtained from the following alkanes? CH3CH2CH2CH3 A. 1 B. 2 C. 4 D.3 E. more complex Part III: Matching question (each question is 2 point, 12 points in total) column A column B 1 Cis/trans-1,2-dimethylcyclopentane D A The bond is rotatable 2 yellow color in alkane combustion H B Radical species 3 Butane J (A+F) C Oxidation number is 3 4 Cl2 + UV light B D We can’t rotate the bond 5 E Oxidation number is -4 G 6 CO2 I (no match) F Staggered anti is the most stable Note: if there is more than one answer matching G in column b, then choice J, if there is no match then choice I. H Particulate carbon I None of the above J More than one answer is correct 5 Good luck- Dr. Haider Namh Sultani