Qualitattive Analysis

Question 1

Ca2+
1)Color after drop dropwise addition of sodium hydroxide solution

2)Effect of adding excess sodium hydroxide solution on the precipate

Answer 1

White

Precipate is insoluble in excess, therefore it remains

Question 2

Al3+
1)Color after drop dropwise addition of sodium hydroxide solution

2)Effect of adding excess sodium hydroxide solution on the precipate

Answer 2

White
Precipate is soluble in excess, it dissolves and forms a colourless solution

Question 3

Zn2+
1)Color after drop dropwise addition of sodium hydroxide solution

2)Effect of adding excess sodium hydroxide solution on the precipate

Answer 3

White
Precipate is soluble in excess, dissolves and turns colourless

Question 4

Pb2+
1)Color after drop dropwise addition of sodium hydroxide solution

2)Effect of adding excess sodium hydroxide solution on the precipate

Answer 4

White
Precipate is soluble in excess, dissolves and forms a colourless

Question 5

Fe2+
1)Color after drop dropwise addition of sodium hydroxide solution

2)Effect of adding excess sodium hydroxide solution on the precipate

Answer 5

Green,turns brown on standing
Precipate is insoluble in excess, therefore it remains

Question 6

Fe3+
1)Color after drop dropwise addition of sodium hydroxide solution

2)Effect of adding excess sodium hydroxide solution on the precipate

Answer 6

Red-Brown
Precipate is insoluble in excess, therefore it remains

Question 7

Cu2+
1)Color after drop dropwise addition of sodium hydroxide solution

2)Effect of adding excess sodium hydroxide solution on the precipate

Answer 7

Blue
Precipate is insoluble in excess, therefore it remains

Question 8

NH4+
1)Color after drop dropwise addition of sodium hydroxide solution

2)Effect of adding excess sodium hydroxide solution on the precipate

Answer 8

No prepitate

Question 9

Ca2+
1)Color after drop dropwise addition of aqueous ammonia solution

2)Effect of adding excessammonia solution solution on the precipate

Answer 9

No precipate

Question 10

Al3+
1)Color after drop dropwise addition of ammonia solutionsolution

2)Effect of adding excessammonia solutionsolution on the precipate

Answer 10

White precipitate forms (Al(OH)3).

Aluminium hydroxide is insoluble in excess NH4OH(aq), therefore it remains

Question 11

Pb2+
1)Color after drop dropwise addition of ammonia solutionsolution

2)Effect of adding excess ammonia solution solution on the precipate

Answer 11

White precipitate forms (Pb(OH)2).

Lead(II) hydroxide is insoluble in excess NH4OH(aq) therefore it remains

Question 12

Zn2+
1)Color after drop dropwise addition of ammonia solutionsolution

2)Effect of adding excess ammonia solution e solution on the precipate

Answer 12

White
Zinc hydroxide (Zn(OH)2) is soluble in excess
dissolves and turns colourless

Question 13

Cu2+
1)Color after drop dropwise addition of ammonia solutionsolution

2)Effect of adding excess ammonia solution solution on the precipate

Answer 13

Blue

Copper(II) hydroxide (Cu(OH)2) is soluble in excess NH4OH(aq).

Precipitate dissolves, forming a deep blue solution.

Question 14

F2+
1)Color after drop dropwise addition of ammonia solutionsolution

2)Effect of adding excess ammonia solution solution on the precipate

Answer 14

Green precipitate forms (Fe(OH)2).

Iron(II) hydroxide is insoluble in excess NH4OH(aq), therefore it remians

Question 15

Fe3+
1)Color after drop dropwise addition of ammonia solutionsolution

2)Effect of adding excess ammonia solution solution on the precipate

Answer 15

Red-brown precipitate forms (Fe(OH)3).

Iron(III) hydroxide is insoluble in excess NH4OH(aq),therefore it remains.

Question 16

Identify
Hydrogen

Answer 16

A colourless gas
Has no smell
Place a lit splint in the gas. A squeky pop is heard and the splint is extinguished

Question 17

Identify
Oxygen

Answer 17

A colourless gas
Has no smell

place a glowing splint in the gas.The glowing splint glows brighter

Question 18

Identify
Carbon Dioxide

Answer 18

A colourless gas
Has no smell

Bubble the gas into lime water,white precipitate forms

Question 19

Ammonia

Answer 19

A colourless gas
Has a pungent Odour

Turns moistred litmus paper blue

Question 20

Hydrogen Chloride

Answer 20

A colourless gas
Has a sharp acid smell

Forms white fumes when
brought neara drop of concentrated ammonia
solution on aglass rod.

Question 21

Sulfur Dioxide

Answer 21

A colourles gas
has a choking smell

Turns acidified
potassium
manganate(VII)
solution from
purple to
colourless.

Turns acidified
potassium
dichromate(VI)
solution from
orange to green.

Question 22

Chlrine

Answer 22

A yellow - green gas
Has a sharp odur us poisonous

Turn moist blue litmus paper to ren then bleahes it white

Question 23

Nitrogen Dioxide

Answer 23

A brown gas
Has a sharp irritaing odour is toxic

Turns moist blue litmus paper to red

Question 24

water Vapour

Answer 24

A colourless gas
Has no smell

turns dry cobalt chlride paper from blue to pink

Turns anhydrous copper sulfate from white to blue

Question 25

Effect of Heat on C032-

Answer 25

Carbon Dioxide is evolved whihc forms a white precipitate in lime water

Question 26

effect of Heat on NO3-

Answer 26

Oxygen is evolved which relights a glowing splint

Question 27

Effect of Heat on NO3-

Answer 27

Brown gas(Nitrogen gas) is evolved and Oxygen is evolved which relights a glowing splint

Question 28

Adding Dilute acid CO32-

Answer 28

Efferevence occurs.Carbon Dioxide is evolved which forms a white precipitae in lime water

Question 29

Adding Dilue acid SO32-

Answer 29

Effevence ocurs,Sulfer dioxide evolved on heating which turs acodfoed potassium manganate solution from purple to colourless

Question 30

Reacting with Concentrated Sulfuric acid CO3^2-

Answer 30

Observation: A white precipitate forms in lime water. Gas Test: Produces carbon dioxide.

Question 31

Reacting with Concentrated Sulfuric acid SO3^2

Answer 31

Observation: Acidified potassium manganate(VII) solution changes from purple to colorless. Gas Test: Produces sulfur dioxide.

Question 32

Reacting with Concentrated Sulfuric acid Cl-

Answer 32

Observation: White fumes form with ammonia gas. Gas Test: Produces hydrogen chloride.

Question 33

Reacting with Concentrated Sulfuric acid Br-

Answer 33

Observation: A red-brown gas is seen. Gas Test: Produces bromine.

Question 34

Reacting with Concentrated Sulfuric acid I-

Answer 34

Observation: A grey-black solid forms which sublimes to form purple vapor if heated. Gas Test: Produces iodine.

Question 35

Reaction with silver nitrate solution followed by aqueous ammonia: Cl-

Answer 35

Precipitate: White precipitate (AgCl) which dissolves forming a colorless solution in aqueous ammonia.

Question 36

Reaction with silver nitrate solution followed by aqueous ammonia: Br-

Answer 36

Precipitate: Cream precipitate (AgBr) which slightly dissolves forming in aqueous ammonia. solution

Question 37

Reaction with silver nitrate solution followed by aqueous ammonia: I-

Answer 37

Precipitate: Pale yellow precipitate (AgI) which remains insoluble in aqueous ammonia.

Question 38

Reaction with barium nitrate solution followed by dilute acid: SO4^2-

Answer 38

Precipitate: White precipitate (BaSO4) which remains insoluble and does not react with dilute acid.

Question 39

Reaction with barium nitrate solution followed by dilute acid: CO3^2-

Answer 39

Precipitate: White precipitate (BaCO3) which dissolves in dilute acid, releasing carbon dioxide.

Question 40

Reaction with barium nitrate solution followed by dilute acid: SO3^2-

Answer 40

Precipitate: White precipitate (BaSO3) which dissolves in dilute acid, releasing sulfur dioxide upon heating.