HomeWAECWAEC Standard for Answering Organic Chemistry
March 15, 2019
WAEC Standard for Answering Organic Chemistry
State two advantages of synthetic polymers over natural polymers.
The expected answers include: – cheaper – more durable – can be recycled – easily moulded – lighter – can be made on demand / tailor made – easily available – can be produced in larger quantity – can be formed fasterDraw the structure of the product formed when one mole of ethyne reacts with two moles of hydrogen bromide and name the product(s).
The product formed is dibromoethene
Explain briefly why benzene is soluble in ethanol but insoluble in water
Benzene and ethanol are organic compounds while water is an inorganic / polar compound / like dissolves like / organic compounds dissolve in organic solvents hence benzene is insoluble in water.
Give the reagent(s) that could be used to distinguish between each of the following pairs of compounds. I. CH3(CH2)2CH2OH and CH3CH2OH II. CH3CH2C =CH and CH3C = CCH3 III. CH3CH2CH2CH3 and CH3CH2C = CH2
i. KMnO4 / I2 / NaOH II. NH3 / AgNO3 // NH3/ CuCl III. Br2 / CCl4 // H+/ KMnO4 // H+ / K2 Cr2 O7, Bromine water (i)
Consider the compound below. CH3CONH2CH2OH (i) Draw the structure of the compound. (ii) Name the functional group(s) present in the compound.
(ii) – Amide – hydroxyl / hydroxy
Give the names of the following compounds: (i) CH3CH=CHCH2CH3; (ii) CH3CH2CH2-C-OH.
(i) 2 – pentene/ pent -2- ene (ii) Butanoic acid
Consider the following compounds:
CH3CH=CHCH3; CH3COOCH2CH3; CH3(CH2)2CH3 and CH3CH(OH)CH2CH3
State the family to which each organic compound belongs.
Give the IUPAC name of each compound.
Arrange the compounds in order of increasing boiling point.
(iii) CH3(CH2)CH3< CH3CH = CHCH3< CH3COOCH2CH3 < CH3CH(OH)CH2CH3 The stronger the forces, the higher the boiling point Vander waals forces exist in CH3CH=CHCH3 and CH3(CH2)2CH3 Dipole – dipole interaction exist in CH3COOCH2CH3 Hydrogen bonding exits in the alkanol.
(c) Ethanol is produced on a large scale by heating ethane with steam.
State two other conditions necessary for the reaction.
Write the balanced chemical equation for the reaction.
State one advantage of this method over the fermentation method.
– High pressure – Acid catalyst OR Conc. H2SO4/H3PO3