Redox Reactions + Organic Chemistry

Question 1

What is loss of electrons

Answer 1

Oxidation

Question 2

What is gain of electrons

Answer 2

Reduction

Question 3

What is oxidation number

Answer 3

It is the number of electrons it has lost or gained in becoming bonded to other elements.

Question 4

What does sec and tert represent

Answer 4

That the hydrogen removed was secondary or tertiary

Question 5

What does iso and neo represent

Answer 5

That there are one or two methyl groups attached to the second last carbon

Question 6

What is chain isomerism

Answer 6

Straight or branched

Question 7

What is functional isomerism

Answer 7

When the position of functional group changes the functional group

Question 8

What is positional isomerism

Answer 8

Position of functional group changes

Question 9

What is metamerism

Answer 9

When two compounds differ in position of alkyl group

Question 10

What are the types of geometrical isomerism

Answer 10

cis - same line
trans - opposite lines

Question 11

What is polarised light

Answer 11

Light that only moves in one plane

Question 12

What is the types of optical activity

Answer 12

dextro = to the right, +
laveo = to the left, -

Question 13

What are enantiomers

Answer 13

Optical isomers which are non-super-imposable mirror images of each other.

Question 14

What is the condition for optical activity

Answer 14

Dissymmetry or chirality

Question 15

What is a racemic mixture

Answer 15

An optically inactive mixture consisting of equal parts of enantiomers

Question 16

What are the two types of stereoisomerism

Answer 16

Conformational and Configurational

Question 17

What does configuration mean

Answer 17

It is the arrangement of atoms in space which characterizes a particular stereoisomer

Question 18

What does retention mean

Answer 18

It means that the spatial arrangement of the atoms arranged to the chiral carbon has not changed

Question 19

What does inversion mean

Answer 19

It means the arrangement of the atoms of the chiral carbon has changed during the reaction

Question 20

What are diastereomers

Answer 20

They are stereoisomers of substances other than enantiomers that do not have mirror image relationships

Question 21

What are meso compounds

Answer 21

They are compounds which are superimposable even though they have a chiral carbon

Question 22

What smell indicates nitrogen

Answer 22

burning feathers

Question 23

What is soda lime

Answer 23

NaOH + CaO

Question 24

Why is CaO used in soda lime

Answer 24

because NaOH is deliquescent and attacks the glass

Question 25

How to detect sulphur in an organic compound

Answer 25

Add lead acetate and acetic acid to sodium extract

Question 26

Why is acetic acid used instead of sulphurc acid in detection of sulphur

Answer 26

Because sulphuric acid will cause the precipitation of lead sulphate. Acetic acid also increases the precipitation of lead acetate due common ion effect

Question 27

Reaction for detection of sulphur with PbS precipitate

Answer 27

Na2S + (CH3COO)2Pb --> PbS + C2H3NaO2

Question 28

Detection of sulphur with purple ppt

Answer 28

Na2S + Na2[Fe(CN)5NO] --> Na4[Fe(CN)5NOS]

Question 29

What is the formula for sodium nitroprusside

Answer 29

Na2[Fe(CN)5NO], Sodium pentacynide nitrosyl ferrate(III)

Question 30

What is the purple ppt formed in detection of sulphur

Answer 30

Na4[Fe(CN)5NOS], sodium pentacynidenitrosyl sulphide ferrate (III)

Question 31

Describe the oxidation process for detection of sulphur

Answer 31

1. Fusion of organic compound + sodium nitrate + sodium carbonate. The sulphur is oxidised to sodium sulphate 2. the fused mass is extracted with water and acidified with HCl 3. BaCl2 is added to form BaSO4 which is insoluble in HCl

Question 32

What are the reactions in detection of sulphur of volatile compounds

Answer 32

3NaNO2 --> 3NaNO2 + 3(O) Na2CO3 + 3(O) + S --> Na2SO4 + CO2 NaSO4 + BaCl2 --> BaSO4 + NaCl

Question 33

Describe the process to form the extract to detect halogens

Answer 33

Add HNO3 to SE extract to eliminate CN and S NaCN + HNO3 --> NaNO3 + HCN(g) Na2S + HNO3 --> NaNO3 + H2S (G) Add AgNO3

Question 34

What indicates chlorine

Answer 34

White ppt soluble in excess of NH4OH AgNO3 + NaCl --> NaNO3 + AgCl AgCl + NH4OH --> H2O + Ag(NH3)2Cl

Question 35

What indicates bromine

Answer 35

Pale yellow ppt sparingly soluble in excess NH4OH

Question 36

What indicates iodine

Answer 36

yellow ppt insoluble in excess NH4OH

Question 37

Estimation of carbon and hydrogen method

Answer 37

Leibig method

Question 38

Formula to calculate mass of carbon

Answer 38

% = (12*increase of weight in KOH * 100)/(44 * mass of organic compound)

Question 39

Formula to calculate mass of hydrogen

Answer 39

(2*increase in weight of U tube*100)/(18*mass of organic compound)

Question 40

Estimation of halogens and sulphur method

Answer 40

Carius method

Question 41

Method to calculate weight of halogen

Answer 41

organic compound is heated with fuming nitric acid and silver nitrate to form silver halide

Question 42

Formula for weight of halogen

Answer 42

At wt of X * weight of silver halide formed * 100 / mol wt of AgX *weight of organic cimpound

Question 43

Describe carius method for sulphur

Answer 43

Add fuming nitric acid to organic compound and then add excess barium chloride

Question 44

Reaction for carius method for sulphur

Answer 44

S + HNO3 --> H2SO4 + NO2 + H2O H2SO4 + BaCl --> BaSO4 + HCl

Question 45

Formula for detection of sulphur

Answer 45

32 * weight of BaSO4 * 100 / 233 *weight of organic compound

Question 46

When does I- effect occur

Answer 46

When the group is more electronegative

Question 47

When does I+ effect occur

Answer 47

When the group is more electropositive

Question 48

What is the order of I+ effect

Answer 48

tertiary> secondary> primary > hydrogen

Question 49

Define inductive effect

Answer 49

It is the permanent displacement of the shared pair of electrons in a carbon chain towards the more electronegative group

Question 50

What is electromeric effect

Answer 50

the complete displacement of a shared pair of electrons of multiple bonds to one of the bonded atoms under the influence of an attacking reagent

Question 51

What is hyperconjugation

Answer 51

It is the interaction between the p orbital and the adjacent carbon hydrogen single-bond

Question 52

What is resonance

Answer 52

the delocalization of pi bond electrons in a conjugated system