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A sample of aspirin (acetyl salicyclic acid) of molecular mass 180, on analysis was found to contain 60% carbon, 4.4% hydrogen and 35.6% oxygen
i.Determine the empirical formula of aspirin
ii. What is the molecular formula of aspirin?
iii. State the technique that can be used to determine the molecular weight of aspirin
In an experiment, ethylbenzoate is hydrolysed. 5cm3 [0.03moles] of ethylbenzoate are mixed with 30cm3 of 2M NaOH solution and heated under reflux for about 15 minutes until all the oily drops have disappeared. The flask is then filled with fractional distillation and the mixture is distilled until the boiling point reaches 750C to give a distillate "A". The content of the flask are allowed to cool and then slowly acidified with concentrated hydrochloric acid when a precipitate "B" separates. This precipitate is then purified by recrystallisation from water.
Sketch the apparatus for heating the mixture under reflux.
Write the equation for the reaction between ethylbenzoate and NaOH solution
before the frost hits thereby preventing the fruit from freezing. Using concepts from
this unit, explain why this helps to save the fruit.
make propanoic anhydride from formaldehyde
in nitration reaction.
Draw Newman and sawhorse projections of various conformations of ethane. Compare the
stabilities of these conformations giving reasons.
Respectively. P does not give a turbid solution with the Lucas reagent. The reaction of p, Q and R with concentrated H2SO4 give X, Y and Z respectively. Only Y shows enantiomerism. Compound D reacts with alcoholic KOH and give Z. i) Draw the structures of A, B, C and D in the boxes given below
