Organic Chem

Question 1

at what conditions does a primary alcohol get dehydrated into alkene and release 1 water molecule

Answer 1

H2so4
170 - 180 C

Question 2

product and conditions for weak dehydration of 2 primary alcohols

Answer 2

140 C h2so4
ether and water

Question 3

what happens when we try to oxidize tertiary alcohol under extreme conditions

Answer 3

alcohol gets dehydrated into alkene, and is then cleaved and oxidized into 1 ketone and 1 aldehyde

Question 4

what is used in sarrett’s oxidation of alcohols?

Answer 4

CrO3
pryidine

Question 5

difference between sarrett’s and collin’s oxidation

Answer 5

collins also uses CH2Cl (dichloromethane) as a solvent along with cro3 and pyridine

Question 6

describe jone’s oxidation of alcohol

Answer 6

cro3 (chromium oxide/trioxide/chromic acid)
H2SO4
and acetone is the solvent.
only one out of the 3 that further oxidizes aldehyde into carboxylic

Question 7

cleavage of diols could be done w kmno4 to get carboxylic acid, could it be done with a weaker regant?

Answer 7

periodic acid (HIO4) gives us two aldehydes

Question 8

what is the dichromate test for

Answer 8

detection of ethanol for drunk drivers
dichromate turns green from orange
acetalaldehyde is formed

Question 9

what is the lucas test for

Answer 9

differentiation of tert/sec/primary alcohols
alcohol reacts with hcl under zinc chloride catalyst to give a clody/oily solution (RCL and h2o)
tert forms immediately whereas primary forms on heating

Question 10

describe the results of the victor meyer’s test for the differentiation of alcohols

Answer 10

1 : blood red
2 : blue
3 : no color

Question 11

how to synthesise ethers using williamson’s synthesis

Answer 11

2 steps
1. acid metal reaction bw alcohol and Na
2. React the sodium alkoxide formed RO-Na+ with R-X (alkyl halide) Sn2 to give us ether and NaX

Question 12

how to syntheisise ethers using halogenoalkanes

Answer 12

React 2 RX with Ag2O at high temp. 2AGX form along with 1 ether

Question 13

ethers react with acyl halides in the presences of …….. to give us?

Answer 13

ZnCl2 catalyst
RX and ester

Question 14

ethers act as a nucleophile and a base to react with strong acid to produce

Answer 14

oxonium ion and then salt
(with hbr, h2so4)
not with HI tho, forms RI and alcohol instead

Question 15

phenol when treated w conc h2so4 and then w conc hno3 give us

Answer 15

2,4,6 - nitrophenol

Question 16

during hydration of alkenes to form alcohols, alkenes are first dissolved in?

Answer 16

conc h2so4

Question 17

esterfication follows which reaction mechanism

Answer 17

nucleophillic sub

Question 18

trans isomers have —- bp but —– mp

Answer 18

low bp due to non polar nature but high mp as they r closely packed

Question 19

the type of isomerism that arises due to shifting of proton from one atom to another in the same molecule is called

Answer 19

tautomerism

Question 20

how many organic compounds r known

Answer 20

over 6 million

Question 21

aliphatic compounds is another name for

Answer 21

acyclic compounds

Question 22

the wolf kishner reduction

Answer 22

ketone/aldehydes —-> alkane
NH2NH2
KOH alc
heat

Question 23

on what basis do we determine which alkene reacts fastest w H2 under hydrogenation condition

Answer 23

the one w least stearic hinderance/ alkyl groups subsitituted on CC

Question 24

list all the dehydrating agents

Answer 24

h2so4 , p2o3, p4o10, h3po4, al2o3

Question 25

order of reactivity of alk to give electrophillic addition reactions

Answer 25

alkene>akyne> alkane

Question 26

how could we produce is cis alkene from an alkyne

Answer 26

hydrogenation reaction H2 and lindlar pd- poisoned catalyst (pt catalyst would further reduce it to alkane)

Question 27

how could we produce a trans alkene from an alkyne

Answer 27

Na and NH3 Na breaks 1 pi bond and donate one electron to one C, forming a radical ion and a carboanion The H goes to the anion and the radical further forms an anion from sodium metal and also accepts H from nh3

Question 28

list electron withdrawing groups which deactivate the benzene ring, making it less reactive

Answer 28

- carbonyl groups CHO, · halogens (F, Cl); · nitriles CN; · nitro groups NO2.

Question 29

list electron donating groups which activate the ring

Answer 29

· alkyl groups; · alcohol groups; · amino groups.

Question 30

aromic compounds burn with yellow sooty flame because

Answer 30

they have high percentage of carbon incomplete combustion

Question 31

why are alkenes more reactive than benzene w.r.t electrophillic sub

Answer 31

Benzene has a cyclic structure with delocalised electrons and with more resonating structures which make it more stable. As it is more stable so it is less reactive.

Question 32

order of reactiivty of alkenes with hydrogen halides is

Answer 32

HI>HBr>HCl>HF

Question 33

ethanenitrile can be converted into ethanoic through -------- intermediate

Answer 33

acetamide

Question 34

the formation of acetic ahnydride from acetic acid follows the mechanism

Answer 34

SN

Question 35

molar mass of formic acid in benzene comes out to be

Answer 35

92

Question 36

nitrobenzene is reduced to phenylamine (aniline) by

Answer 36

Sn/HCL

Question 37

phenylamine + CH3Cl + 3KOH --->

Answer 37

phenyl isocyanide C6H5CN + 3KCL +3H2O

Question 38

the primary secondary and tertiary amines can be distinguised by

Answer 38

hinsberg's reagent C6H5SO2Cl 1 : alkali soluble benzene sulphonamide 2 : insoluble version of 1 3 does not react

Question 39

what is the hoffman bromoamide reaction/ degradation reaction

Answer 39

when primary amine reacts w Br and NaOH then one carbon less primary amine will form

Question 40

the leaving group in SN2 reaction is

Answer 40

a good leaving group is a weak base

Question 41

what is a good leaving group

Answer 41

a small negatively charged ion that can easily leave a molecule without causing much disruption (hso4- and br-). OH- is a bad leaving group because its a strong nucleophile and has high charge to size ratio so very attracted to carbon

Question 42

in a reaction havig both alkyl halide and base the base will attack on ----?

Answer 42

beta hydrogen

Question 43

what is cannizaro reaction

Answer 43

carbonyl compound reacts with naoh or koh to form one cooh (oxidized) and alcohol (reduced) oxidation will occur on carbon w less stearic hinderance(bulky groups) and electron withdrawing groups.

Question 44

on dry distillation of calcium methanoate, what is produced

Answer 44

acetaldehyde (ethanal ) and CO2

Question 45

carbonyl compounds undergo nucleophillic addition because

Answer 45

electronegativity difference and pi bond

Question 46

FeCl3 is used to differentiate

Answer 46

phenols : purple alcahols : colorless

Question 47

what is clemenson reduction

Answer 47

carbonyl group is reduced to CH2 when treated with amalgamated zinc and conc hcl

Question 48

when acetylene is passed thru hot iron tube at 400 C it gives

Answer 48

benzene

Question 49

non polar product is formed in what type of reaction (E or S)

Answer 49

Elimination

Question 50

a better leaving group has following characteristics

Answer 50

- stable anion - large sized - favors sn1 instead of sn2

Question 51

formation of phenols in dow’s method is

Answer 51

aromatic nucleophilic sub of chlorobenzene to phenol

Question 52

most acidic alcohol

Answer 52

methanol

Question 53

which gives positive iodoform test

Answer 53

ethanol and 2-alcohol and methyl ketones

Question 54

phenol reacts with acyl halide to give

Answer 54

aromatic ester

Question 55

what reacts w NaHSO3 to give white ppt?

Answer 55

aldehydes and small methyl ketones

Question 56

oximes are formed upon reaction of aldehydes or ketones with

Answer 56

hydroxyl amine

Question 57

acetone can be prepared by dry distillation of?

Answer 57

calcium acetate

Question 58

Aldehydes or ketones possessing alpha hydrogen undergo?

Answer 58

aldol condensaition those that dont : unergo cannizaro reaction

Question 59

Carboxylic acids can be prepared from oxidation of ketones by

Answer 59

pop off rule 🍑