Organic Chemistry Answers

    A solution containing equal concentrations of a weak acid and its conjugate base has a pH of 5.45. What is the dissociation constant for the acid?

with the aid of a tautomerism reaction, predict how penta-2-ol can be formed from penta-2-yne

A manufacturer of paint claims that a gallon (3.78 L) of latex paint can cover 365 ft² of the surface of a wall in a single coating. The paint manufacturer also claims that one single coating of an entire wall will be 3.40 mm thick. 

Is this a case of false advertising? Yes or No? Elaborate your answer by providing a calculation (handwritten, upload a pdf).

You may use the following conversions: 12 in = 1 ft, 2.54 cm = 1 in

(a) 1-bromonaphthalene undergoes nucleophilic substitution reaction to give two isomeric products

i) Write a posible mechanism to explain the formation of the two products, given that the reaction involves the intermediacy of a benyne-type species. ii) In terms of orbital overlaps, briefly but clearly discuss how the ∏-bonds in this benzyne-type intermediate are formed. Explin whether or not this benzyne-type intermediate is aromatic. (b) Starting from nitrobenzene and any other benzene derivative of your choice, show by a reaction scheme how the following azo compound could be synthesised. No mechanism is required but you must show all reagents and intermediate products that are formed.

(a) Write the IUPAC names of the following structures:

(i) 1,3-dimethoxybicyclo[2.2.1]heptane                                                                        

(ii) bicyclo[2.2.1]hept-5-en-2-one                                                           

Two stereoisomers of 1-tert-butyl-2-bromo-3-methylcyclohexane are shown below. These are referred to in the questions that follow.

(a) Draw the possible chair conformers for each of the above stereoisomers and indicate the more stable conformer in each pair by calculating total strain energy. [4 marks]

(b) Perform the ring flip for the most stable conformer for each structure and comment using relative energies of the chair conformations suggesting which form is more stable. [4 marks]

(c) If each stereoisomer is exposed to E2 elimination conditions, draw the structure(s) of the E2 elimination product(s) that may be obtained for each of them. Show clearly how you arrive at the answers (use mechanisms). [4 marks]