Principles Related to Practical Chemistry

Question 1

Alcohols react with Cerric ammonium nitrate to give

Answer 1

A Red Complex [Ce(NO₃)₄(ROH)₃]

Question 2

Phenol with Neutral Ferric Chloride gives

Answer 2

Violet Colour
[Fe(OC₆H₅)₆]^3-

Question 3

Resorcinol with Neutral Ferric Chloride gives

Answer 3

Blue/Violet Colour

Question 4

o-,m-&p- cresols with Neautral Ferric Chloride gives

Answer 4

Blue/Violet Colour

Question 5

Catechol with Neutral Ferric Chloride gives

Answer 5

Green which rapidly darkens

Question 6

1-Naphtol & 2-Naphtol with Neautral Ferric Chlorde gives

Answer 6

No Colour

Question 7

Phenol with Phtalein Dye gives

Answer 7

Pink Colour

Question 8

o-Cresol with Phtalein Dye gives

Answer 8

Red Colour

Question 9

m-Cresol with Phtalein Dye gives

Answer 9

Bluish-Purple Colour

Question 10

p-Cresol with Phtalein Dye gives

Answer 10

No Colour

Question 11

Catechol with Phtalein Dye gives

Answer 11

Usually blue, takes longer time to appear

Question 12

Resorcinol with Phtalein Dye gives

Answer 12

Green fluorescent colour of Fluorescein

Question 13

Carbonyl Compounds with 2,4-DNP gives

Answer 13

Orange/Red/Yellow Crystals

Question 14

Why is Benedit Solution preferred over Fehlings Solution?

Answer 14

Benedict Solution is Stable while Fehling’s Solution is unstable
[Fehling’s Solution A & Fehling’s Solution B are stable independently]

Question 15

BiCarbonate Test liberates CO₂ with:

Answer 15

Sulphonic Acid
Carboxylic Acid
Picric Acid
2,4-DiNitroPhenol

Question 16

Universal Test for Primary Amine is

Answer 16

Carbylamine/Isocyanide Test

Question 17

Primary Amine is ___ in Conc. HCl

Answer 17

Soluble

Question 18

Test for distinguishing between Aliphatic Primary Amine and Aromatic Primary Amine

Answer 18

Azo Dye test

Question 19

Azo Dye Test of Aromatic Primary Amine gives

Answer 19

Scarlet Red Dye

Question 20

During Preparation of Mohr Salt, dil. H₂SO₄ is added to:

Answer 20

Prevent Hydroysis of Fe²⁺ to Fe(OH)₂

Question 21

During preparation of Mohr Salt, strong heating is avoided to

Answer 21

Prevent Oxidation of Fe²⁺ to Fe³⁺

Question 22

Formula for Mohr’s Salt

Answer 22

[FeSO₄.(NH₄)₂SO₄.6H₂O]

Question 23

Formula for Potash Alum

Answer 23

K₂SO₄.Al₂(SO₄)₃.24H₂O

Question 24

Soda Alum consists of

Answer 24

Na⁺
Al³⁺

Question 25

Chrome Alum consists of

Answer 25

K⁺ Cr³⁺

Question 26

Ferric Alum consists of

Answer 26

K⁺ Fe³⁺

Question 27

Use of Potash Alum

Answer 27

To Purify Drinking Water

Question 28

Aniline Yellow is

Answer 28

p-aminoazobenzene

Question 29

Aniline Yellow is prepared from

Answer 29

Diazoamino Benzene

Question 30

End Point is

Answer 30

Practical end of titration shown by the indicator

Question 31

Equivalence Point/Stoichiometric End Point is

Answer 31

Theorethical end point of Titration

Question 32

Titration error is

Answer 32

Difference between End Point and Equivalence Point

Question 33

Phenolphtalein is

Answer 33

Weak Acid Dissociates in pH 8-10 White -> Pink

Question 34

Methyl Orange is

Answer 34

Weak Base Dissociates in pH 3.1-4.5 Yellow -> Pinkish Red

Question 35

Colourless form of Indicators is

Answer 35

Benzenoid Form

Question 36

Coloured form of Indicators is

Answer 36

Quinanoid Form

Question 37

Indicator for SA+SB

Answer 37

HPh or MeOH

Question 38

Indictor for SA+WB

Answer 38

MeOH

Question 39

Indicator for WA+SB

Answer 39

HPh

Question 40

Indicator for WA+WB

Answer 40

no Indicators

Question 41

Preliminary Test with dil. H₂SO₄ is for

Answer 41

CO₃^2- S^2- SO₃^2- NO₂^- CH₃COO^-

Question 42

Starch Test is given by

Answer 42

Nitrite NO₂^-

Question 43

Griss-Ilosvary test is given by

Answer 43

Nitrite NO₂^-

Question 44

Preliminary Test conc. H₂SO₄ is given by

Answer 44

Cl^- Br^- I^- NO₃^- C₂O₄^2-

Question 45

Colour of Chromyl Chloride CrO₂Cl₂

Answer 45

Reddish-Brown Vapours

Question 46

Color of Na₂CrO₄ and PbCrO₄

Answer 46

Yellow

Question 47

Colour of AgCl

Answer 47

White

Question 48

Colour of CrO₅

Answer 48

Blue

Question 49

Bromide on starch Test gives

Answer 49

Yellow Colour

Question 50

Iodide on starch Test gives

Answer 50

Blue Colour

Question 51

Brown Ring is

Answer 51

Confirmation of Nitrate ion NO₃^- [Fe(H₂O)₅NO]SO₄ NitrosoFerrous Sulphate

Question 52

Colour of PbSO₄ and BaSO₄

Answer 52

White

Question 53

Colour test for Fe²⁺ or Fe³⁺

Answer 53

Light Green, Yellow, Brown

Question 54

Colour Test for Cu²⁺

Answer 54

Blue

Question 55

Colour Test for Ni²⁺

Answer 55

Bright Green

Question 56

Colour Test for Co²⁺

Answer 56

Blue, Violet, Red, Pink

Question 57

Colour Test for Mn²⁺

Answer 57

Light Pink

Question 58

Dry Heating Test of Cu²⁺

Answer 58

Cold -> **Blue** Hot -> **White**

Question 59

Dry Heating Test of Fe²⁺

Answer 59

Cold -> **Green** Hot -> **Dry White or Yellow**

Question 60

Dry Heating Test of Zn²⁺

Answer 60

Cold -> **White** Hot -> **Yellow**

Question 61

Dry Heating Test of Co²⁺

Answer 61

Cold -> **Pink** Hot -> **Blue**

Question 62

Flame test is done in

Answer 62

Non-luminous flame

Question 63

Flame Test for Cu²⁺

Answer 63

Colour of Flame by eye -> **Green with Blue Centre** Colour of Flame through Blue Glass -> **Green with Blue Centre**

Question 64

Flame test for Sr²⁺

Answer 64

Colour of Flame by eye -> **Cimson Red** Colour of Flame through Blue Glass -> **Purple**

Question 65

Flame Test for Ba²⁺

Answer 65

Colour of Flame by eye -> **Apple Green** Colour of Flame through Blue Glass -> **Bluish Green**

Question 66

Flame Test for Ca²⁺

Answer 66

Colour of Flame by eye -> **Brick Red** Colour of Flame through Blue Glass -> **Green**

Question 67

Borax Test of CuSO₄ under non-luminous flame gives

Answer 67

Cupric Metaborate Cu(BO₂)₂ Blue-Green beads

Question 68

Heating of Cupric Metaborate in Lummious Flames gves

Answer 68

Red & Opaque Metallic Copper

Question 69

Borax Bead test of Cu²⁺ in non-luminous flame

Answer 69

Cold-> **Blue** Hot-> **Green**

Question 70

Borax Bead test of Cu²⁺ in luminous flame

Answer 70

Cold-> **Red Opaque** Hot -> **Colourless**

Question 71

Borax Bead test of Ni²⁺ in non-luminous flame

Answer 71

Cold-> **Reddish Brown** Hot-> **Violet**

Question 72

Borax Bead test of Ni²⁺ in luminous flame

Answer 72

Cold-> **Grey** Hot-> **Grey**

Question 73

Borax Bead test of Mn²⁺ in non-luminous flame

Answer 73

Cold-> **Light Violet** Hot-> **Light Violet**

Question 74

Borax Bead test of Mn²⁺ in luminous flame

Answer 74

Cold-> **Colourless** Hot-> **Colourless**

Question 75

Borax Bead test of Fe²⁺ in non-luminous flame

Answer 75

Cold-> **Yellow** Hot-> **Yellow-Brown**

Question 76

Borax Bead test of Fe²⁺ in luminous flame

Answer 76

Cold-> **Green** Hot-> **Green**

Question 77

In Charcoal Cavity Test/Blowpipe Test, for Oxidising Flame, Blowpipe is

Answer 77

1/3 inserted into flame

Question 78

In Charcoal Cavity Test/Blowpipe Test, for Reducing Flame, Blowpipe is

Answer 78

held to surface of flame

Question 79

Charcoal Cavity Test/Blowpipe Test of Pb

Answer 79

Yellow Residue when hot & grey metal when cold

Question 80

Charcoal Cavity Test/Blowpipe Test of As

Answer 80

White Residue with the odour of garlic

Question 81

Charcoal Cavity Test/Blowpipe Test of Cd

Answer 81

Brown Residue

Question 82

Charcoal Cavity Test/Blowpipe Test of Zn

Answer 82

Yellow Residue when hot & white when cold

Question 83

Cobalt Nitrate Test of Zn

Answer 83

ZnO.CoO Rinmann's Green

Question 84

Cobalt Nitrate Test of Mg

Answer 84

MgO.CoO Pink

Question 85

Cobalt Nitrate Test of Al

Answer 85

Al₂O₃.CoO Blue

Question 86

Salt is insoluble if it doesn't dissolve in

Answer 86

Aqua-Regia

Question 87

Aqua Regia is

Answer 87

1:3 mixture of Conc. HNO₃+Conc. HCl

Question 88

Group Zero Cation

Answer 88

NH₄⁺

Question 89

Group I Cation

Answer 89

Pb²⁺

Question 90

Group II Cations

Answer 90

Pb²⁺, Cu²⁺

Question 91

Group III Cations

Answer 91

Al³⁺, Fe³⁺

Question 92

Group IV Cations

Answer 92

Ni²⁺, Zn²⁺

Question 93

Group V Cations

Answer 93

Ba²⁺, Ca²⁺

Question 94

Group VI Cation

Answer 94

Mg²⁺

Question 95

Colour of PbI₂

Answer 95

Yellow

Question 96

Colour of Na₂[Pb(OH)₄]

Answer 96

White

Question 97

Colour of PbS and CuS

Answer 97

Black

Question 98

Colour of As₂S₃

Answer 98

Yellow

Question 99

Colour of [Cu(NH₃)₄]SO₄

Answer 99

Deep Blue Soluble Complex

Question 100

Colour of Cu₂[Fe(CN)₆]

Answer 100

Chocolate Brown

Question 101

Colour of Al(OH)₃

Answer 101

White Gelatinous

Question 102

Colour of Fe(OH)₃

Answer 102

Brown

Question 103

Lake Test is for

Answer 103

Alumnium (Al(OH)₃ adsorbs to blue colour to form lake)

Question 104

Colour of Fe₄[Fe(CN)₆]₃

Answer 104

Prussian Blue or Green

Question 105

Soluble Prussian Blue is

Answer 105

KFe[Fe(CN)₆]

Question 106

Colour of NiS and CoS

Answer 106

Black

Question 107

Colour of MnS

Answer 107

Flesh

Question 108

Colour of ZnS

Answer 108

White

Question 109

Clour of Zn₂[Fe(CN)₆]

Answer 109

White/Bluish-White

Question 110

Colour of [Ni(dmg)₂]

Answer 110

Wine Red (dsp²)

Question 111

Colour of Mg(NH₄)PO₄

Answer 111

White

Question 112

Diameter of Dispersed Particles in a Colloid

Answer 112

1nm-1000nm

Question 113

Lyophilic Colloids

Answer 113

Egg Albumin sol (Egg White + NaCl) Starch/Gum sol (Starch/Gum in hot water)

Question 114

Lyophobic Colloids

Answer 114

Fe(OH)₃/Al(OH)₃ sol As₂S_{3 (from As2O3)}

Question 115

Main Reason for Lyophilic Colloids

Answer 115

Solvent Layer around oloid due to solvation

Question 116

Main Reason for Lyophobic Colloids

Answer 116

Charge

Question 117

Clock Reaction is

Answer 117

Starch + I₂ In presence of S₂O₃^2-