Organic Nitrogen Compounds

Front 1

what does the strength of the bases ammonia and amines depend on?

Back 1

the strength depends on the availability of the lone of of electrons from the nitrogen to bond with H+

Front 2

explain why the strength of bases is in such a order

ethylamine> ammonia > phenylamine

Back 2

ethylamine has an alkyl group which is electron donating so the lone pair of electrons in N atom is more available to bond with H+, phenylamine has the lone pair of electrons from N atom delocalised into the benzene ring due to voerlap p orbital, less available to form coordinate dative bond with H+

Front 3

3 ways to make an amines?

Back 3

1) nucleophilic substitution of a halogenoalkane and ammonia(use excess hot ethanolic ammonia)

2)KCN in ethanol refluxed with halogenoalkane, then nitrile is reduced by hydrogen gas, with nickel catalyst or LiAlH4 in dry ether

3)use LiAlh4 to reduce amides to amines

Front 4

how do you prepare phenylamine?

Back 4

reduce nitrobenzene

by heating with Sn & conc HCl, releasing h20 as byproduct

Front 5

name the diazonium ion in it's chemical formula

Back 5

C6H5N2 +

Front 6

what is the name of the precipitate formed from reaction of phenylamines and bromine(aq) , what is the colour?

Back 6

2,4,6- tribromophenylamine, white ppt

Front 7

what is the temp condition for reaction of phenylamine and aq bromine and how is the condition kept and why is it needed?

Back 7

temp must be at below 10 degrees using ice because diazonium salt is unstable n can decompose to give N2 gas

Front 8

for diazotisation, give the chemical equation for producing nitrous acid in the same test tube as phenylamine.

Back 8

NaNO2 + HCl --> HNO2 + NaCl

Front 9

what is the first step in synthesis of dyes?

Back 9

production of benzenediazonium chloride is first,

phenylamine + nitrous acid + HCl---> benzenediazonium chloride + 2 H2O

Front 10

what is the second step for formation of dyes?

Back 10

reaction of diazonium salt with alkaline solution of phenol in coupling reaction.

the diazonium ion substitutes into position 4 of the phenol

Front 11

why are dyes stable?

Back 11

the delocalised pi bonding system extends between the two benzene rings through the NN group

Front 12

how do you make an amide?

Back 12

reacting the acyl chloride with conc NH3 solution or ethylamine to give a substituted amide

Front 13

what is produced in acid and alkali hydrolysis of amides?

Back 13

RCOOH + RNH2 or RNH3+Cl- in excess HCL

RCOO-Na+ + RNH2 in alkali

Front 14

what is electrophoresis used for?

Back 14

to separate , identify and purify proteins

Front 15

why can't the lone pair of electrons from the nitrogen in the amide donate to an electron deficient species such as H+?

Back 15

there is an electron withdrawing oxygen and the lone pair of electrons are drawn towards it making it unavailable

Front 16

what is electrophoresis?

Back 16

it is a separation technique based on mobility of ions in an electric field

positive ions move to negative electrode and vice versa

ions have different migration rate depending on charge

Front 17

amine groups react with excess acid to produce what?

Back 17

ammonium salts

Front 18

what happens when you react CH3NH2 + HCl?

Back 18

CH3NH2 + HCl--> CH3NH3+Cl-

Front 19

difference in condition of reacting a benzene group with NO2+ and phenol with NO2+?

Back 19

di HNO3 in room temp for phenol and NO2+

but for benzene, you need conc HNO3 and 55 degrees