qualitative analysis

Question 1

sodium hydroxide
no ppt formed
on heating gas evolved turns moist red paper blue

Answer 1

NH4+
Ammonium

Gas evolved is ammonia

Question 2

sodium hydroxide
white ppt formed, insoluble in excess

ammonia
no ppt

Answer 2

Ca2+
Calcium

Question 3

sodium hydroxide
white ppt formed, soluble in excess to form colourless solution

ammonia
white ppt formed, insoluble in excess

Answer 3

Al3+

Question 4

sodium hydroxide
white ppt formed, soluble in excess

ammonia
white ppt formed, insoluble in ecess

Answer 4

Pb+

Question 5

sodium hydroxide
white ppt formed, soluble in excess

ammonia
white ppt formed, soluble in excess

Answer 5

Zn2+

Question 6

sodium hydroxide
light blue ppt formed, insoluble in excess

ammonia
blue ppt formed, soluble in excess to form dark blue solution

Answer 6

Cu2+

Question 7

sodium hydroxide
green ppt formed, insoluble in excess

ammonia
green ppt formed, insoluble in excess

Answer 7

Fe2+

Question 8

sodium hydroxide
reddish brown ppt formed, insoluble in excess

ammonia
reddish-brown ppt formed, insoluble in excess

Answer 8

Fe3+

Question 9

Sodium Hydroxide
no visible reaction

ammonia
no visible reaction

Answer 9

Na+
K+

Question 10

Test for carbonate
CO3 2-

Answer 10

add dilute hydrochloric acid
pass the gas evolved into limewater (calcium hydroxide)

Question 11

Observation for carbonate

Answer 11

Effervescence is observed. the gas evolved forms a white ppt with lime water

Question 12

test for chloride
Cl-

Answer 12

add dilute nitric acid then add aqueous silver nitrate

Question 13

observation for chloride

Answer 13

a white ppt formed, insoluble in dilute HNO3

Question 14

test for iodide
I-

Answer 14

add dilute nitric acid then add aqueous silver nitrate

Question 15

observations for iodide

Answer 15

a yellowppt formed, insoluble in diluteHNO3

Question 16

test for nitrate
NO3-

Answer 16

add aq sodium hydroxide, then add aluminium foil. heat the mixture and test the gas evolved with moist red litmus paper

Question 17

observations for nitrate

Answer 17

colorless gas evolved turns moist red litmu paper blue.
gas is ammonia

Question 18

test for sulfate
SO4 2-

Answer 18

i) add nitric acid then add aq barium nitrate

or

ii) add hydrochloric acid then add aqueous barium chloride

Question 19

observations for sulfate

Answer 19

i) a white ppt formed, insoluble in dilute HNO3-

ii) a white ppt formed, insoluble in dilute HCL

Question 20

solubility of SPA salts

Answer 20

all spa salts - sodium, potassium, and ammonium salts are soluble

Question 21

solubility of carbonate

Answer 21

all carbonates are insoluble EXCEPT for SPA carbonates

Question 22

solubility of nitrates

Answer 22

all nitrates are soluble

Question 23

solubility of chlorides

Answer 23

all chlorides are soluble except for LS
- Lead (II) chloride
- Silver chloride

Question 24

solubility of sulfates

Answer 24

all sulfates are soluble except for CLB
- Calcium sulfate
- lead (II) sulfate
- barium sulfate

Question 25

solubility of iodides

Answer 25

all iodides are soluble except for - Lead (II) iodide - Silver iodide

Question 26

Hydrogen Colour and odour Test Observation

Answer 26

Colourless and odourless Place a lighted splint into the gas Lighted splint extinguishes with a 'pop' sound

Question 27

Oxygen Colour and odour Test Observation

Answer 27

colourless and odourless Place a glowing splint into the gas Glowng splint reignites

Question 28

Carbon dioxide Colour and odour Test Observation

Answer 28

colourless and odourless pass the gas into lime water(calcium hydroxide) gas evolved forms a white ppt w limewater

Question 29

chlorine Colour and odour Test Observation

Answer 29

greenish-yellow gas w a pungent smell use a piece of moist blue litmus paper moist blue litmus paper turns red, then bleached (white)

Question 30

sulfur dioxide Colour and odour Test Observation

Answer 30

colourless with a pungent smell i) pass the gas into acidified potassium manganate (VII) ii) use a piece of moist blue litmus paper i) the purple acidified potassium manganate (VII) decolourises ii)moist blue litmus paper turns red

Question 31

ammonia Colour and odour Test Observation

Answer 31

colourless gas with a pungent smell i) use a piece of moist red litmus paper ii)with hydrogen chloride i)moist red litmu paper turns blue ii) white smoke is observed

Question 32

water vapour Colour and odour Test Observation

Answer 32

colourless, odourless (condenses on the cooler part of the test tube) i)use anyhydrous copper (II) sulfate ii)use cobalt (II) chloride paper i) anhydrous copper(II) sulfate changes from white to blue ii) cobalt (II) chloride paper changes from blue to pink