Worksheetschemyorga1
Total questions: 25
Worksheet time: 6mins
What is an electrophile?
it is a free radical
it is a Lewis acid
it is a Lewis base
It carries a negative charge
Which of the following can act as a free radical?
chlorine atom
chlorine molecule
CH3+ ion
chloride ion
HCOOCH3 and CH3COOH are a pair of
optical isomers
geometrical isomers
chain isomers
functional group isomers
Which compound has tertiary carbon atom?
butane
ethylbenzene
methylpropane
cyclohexane
Compounds having the same molecular formula but are mirror images are called
allotropes
isotopes
enantiomers
structural isomers
2-chlorobutanoic acid is more acidic than 4-chlorobutanoic acid because
it has higher solubility in water
its carboxylate anion is less stable
it forms a stronger conjugate base
of the more effective inductive effect of Cl atom towards the carboxyl group
Which of the following reagents does not react with propene?
acidified KMnO4
Hydrogen chloride
chlorine gas
aqueous ammonia
An organic compound Z undergoes a catalytic hydrogenation reaction. Z also reacts with hydrogen bromide to form 2-bromopropane. The possible structural formula of Z is
CH2=CH2
CH3CH2CH3
CH3CH=CH2
CH3CH(OH)CH3
Ethene and ethane can be differentiated by using
I acidified KMnO4
II bromine in the absence of light
III concentrated sulphuric acid
IV hydrogen gas
I and II only
I and III only
II and III only
I and IV only
Which of the following alkenes when oxidised by acidified potassium dichromate(VI) will liberate carbon dioxide?
I CH2=CH2
II CH3CH=CH2
III CH3CH=CHCH3
IV CH3CH(OH)CH=CH2
I and II
I, II and IV
IV only
I, II, III and IV
The principle reaction of benzene is
polymerisation
condensation
addition
substitution
Benzene reacts with a mixture of concentrated nitric acid and concentrated sulphuric acid to produce nitrobenzene. What is the function of sulphuric acid in the reaction?
to protonate the nitric acid
to eliminate the water produced
to prevent disubstitution from occuring
to prevent oxidation of benzene by nitric acid
Which of the following reagents can be used to distinguish between benzene and methylbenzene?
concentrated nitric acid
chlorine in presence of aluminium chloride
alkaline potassium manganate(VII)
bromine in the dark
Toluene reacts with chlorine to form 4-chlorotoluene. Which statement is true about the reaction?
The species formed in the initial step of the reaction is Cl+ ion.
The reaction mechanism is free radical substitution
The reaction also produces 3-chlorotoluene
The reaction is catalysed by UV light
In the reaction between benzene and 1-chloropropane in the presence of aluminium chloride, the first step involves the formation of the carbonium ion.
This is made possible because
The AlCl4- ion formed has an octet configuration
aluminium chloride exists as a dimer at room conditions
the aluminium atom in AlCl3 has an incomplete octet
the first electron affinity of aluminium is low
Chloroethane hydrolyses easily in an aqueous solution of sodium hydroxide whereas hydrolysis of chlorobenzene requires high temperature and pressure. Which statement best explains the low reactivity of chlorobenzene towards hydrolysis?
The non-bonding electrons of Cl are delocalised into the benzene ring
The Cl atom withdraws the electron clouds from the benzene ring
The Cl atom is strongly bonded to the benzene ring
The C-Cl bond in chlorobenzene is shorter
Which of the following reagents will react with both chlorocyclohexane and chlorobenzene?
Ethanolic potassium hydroxide
Magnesium in dry ether
Hydrogen in the presence of nickel
concentrated ammonia
Which of the following compounds will be formed when 2-bromobutane is heated with ethanolic potassium hydroxide?
2-butanol
1-butanol
2-butene
potassium butanoate
Which of the following reagents will react with propylmagnesium chloride to produce a secondary alcohol?
methanal
Phenylethanal
Phenylethanone
Ethanoic acid
Which of the following statements about phenol is correct?
Phenol reacts with sodium hydrogen carbonate to release carbon dioxide
Phenol is a weaker acid than ethanol
phenol dissolves in aqueous sodium hydroxide
phenol forms a red precipitate with aqueous chlorine
Which of the following will react with both phenol and ethanol?
sodium hydroxide
sodium
bromine water
acidified potassium manganate(VII)
When an optically active substance Y is heated with chromic acid, the product formed is not optically active and does not react with alkaline iodine. Y could be
(CH3)2CH(OH)CH3
CH3CH2CH2CH(OH)CH3
CH3CH2CH(OH)CH2CH3
C6H5CH(OH)CH2CH3
which of the following reagents can be used to differentiate between ethanal and other aldehydes?
Fehling's solution
Tollen's reagent
concentrated sulphuric acid
alkaline iodine solution
Compound X has the following properties.
I Forms an orange precipitate with 2,4-dinitrophenylhydrazine
II Forms a yellow precipitate when warmed with alkaline iodine
Compound X is
C6H5CHO
C6H5CH(OH)CH3
C6H5COCH3
C6H5COOCH3
Which of the following statement is not true?
Addition of HCN to a carbonyl compound changes the hybridisation of the carbonyl carbon from sp2 to sp3
the carbonyl carbon atom acts as a nucleophile
In general, aldehydes are more reactive than ketones towards nucleophiles
Addition of HCN to a carbonyl compound is catalysed by a base
