Which of the following will not form a yellow precipitate on heating with an alkaline solution of iodine?
(a) CH3CH(OH)CH3 (b) CH3CH2CH(OH)CH3
(c) CH3OH (d) CH3CH2OH
(c) An organic compound form yellow precipitate of iodoform with I2 in presence of alkali, if it has
CH3CO- group directly or it has group.
(a) CH3CH(OH)CH3 + I2 CH3COCH3 + 2HI + 3NaI + CH3COONa + 3H2O
CH3COCH3 + 3I2 + 4NaOH CHI3 + 3NaI + CH3COONa + 3H2O
(b) CH2-CH2CH(OH)CH3 + I2 + 2HI
It gives iodoform test
(c) CH2OH + I2 HCHO + 2HI
It does not have methyl ketone group, so it does not give yellow ppt with I2 in presence of alkali.
(d) CH3CH2OH + I2 + 2HI
It gives iodoform test
presence of -COCH3, it gives Haloform reaction.
n-propyl alcohol and iso-propyl alcohol can be chemically distinguished by which reagent
(c) oxidation with potassium dichromate
(c) n-propyl alcohol and iso-propyl alcohol gives different products on oxidation with
n-propyl alcohol Propionaldehyde
Iso-propyl alcohol Acetone
Among the following sets of reactants which one produces anisole?
(a) CH3CHO, RMgX
(b) C6H5OH, NaOH, CH3I
(c) C6H5OH, neutral FeCl3
(d) C6H5-CH3, CH3COCl, AlCl3
(b) Williamson's synthesis
Consider the following reaction,
EthanolX Y Z
The product Z is
In the following sequence of reactions,
the end product C is
(a) acetone (b) methane
(c) acetaldehyde (d) ethyl alcohol
In the presence of carboxylic acid reduce in alcohols, directly.
Which one is formed when sodium phenoxide is heated with ethyl iodide?
(b) Ethyl phenyl alcohol
(d) None of the above
(a) When sodium phenoxide (C6H5ONa) is heated with ethyl iodide (C2H5I) it forms ethyl phenyl ether which is also called phenetole. This reaction is called Williamson's synthesis.
When phenol is treated with an excess of bromine water, it gives
(a) m-bromophenol (b) o- and p-bromophenols
(c) 2,4-dibromophenol (d) 2,4,6-tribromophenol
(d) Phenol reacts with bromine water (aqueous solution to give a precipitate of 2,4,6 -tribromophenol) due to polar solvent.
Identity Z in the sequence of reactions,
CH3CH2CH2CH2BrBromo-butane (1 product)
CH3CH2CH2CH2BrCH3CH2CH2CH2OC2H5 (williamson's synthesis)
Reaction of with RMgX leads to formation of
(a) RCHOHR (b) RCHOHCH3
(c) RCH2CH2OH (d)
Reaction of ethyl formate with excess of CH3MgI followed by hydrolysis gives
(1) n-propyl alcohol (2) ethanol (3) isopropyl alcohol (4) propanal
(3) Ethyl formate on reaction with excess of CH3MgI, followed by hydrolysis gives a secondaty alcohol i.e. isopropyl alcohol.