Welcome to the Quiz!
This quiz contains 11 questions from a mix of 1 subtopics.
How is phenylamine prepared from nitrobenzene?
by steam distillation
by neutralisation with sodium hydroxide
by reduction with tin and concentrated HCl
by oxidation with tin and HCl
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How is phenylammonium chloride converted to phenylamine?
by steam distillation
by reaction with aqueous bromine
by neutralisation with sodium hydroxide
by heating under reflux
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What type of reaction occurs when phenylamine reacts with aqueous bromine?
oxidation
electrophilic substitution
neutralisation
reduction
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In the reaction of phenylamine with aqueous bromine, at which positions of the benzene ring does electrophilic substitution occur?
2, 4, and 6
4, 5, and 6
1, 2, and 3
1, 3, and 5
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How many steps are involved in the synthesis of azo dyes?
4
2
3
1
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What is the first step in the synthesis of azo dyes?
coupling reaction with phenolate ion
reduction of nitrobenzene
neutralisation of phenylammonium ion
diazotisation of phenylamine
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What is the purpose of keeping the diazotisation reaction below 10°C?
to slow down the rate of the diazotisation
to accelerate the formation of the diazonium ion
to increase the yield of the azo dye
to prevent the decomposition of the diazonium ion
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What type of reaction occurs in the second step of azo dye synthesis?
oxidation
neutralisation
electrophilic substitution
reduction
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Under what conditions does the coupling reaction between the diazonium ion and phenol occur?
acidic
neutral
alkaline
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What is the distinctive feature of azo dyes?
COO linkage
CONH linkage
N=N linkage
N≡N linkage
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How can dyes of various colours be synthesised from the same benzenediazonium ion?
by changing the reaction temperature
by using different solvents
by coupling the ion with different aromatic compounds
by altering the ion concentration
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