Effect Of Heat On Salts

Question 1

Name five methods to identify cations and anions.

Answer 1

Colour of salt
Solubility of salt
Gas test
Effect of heat on the salt
Confirmatory test for cations

Question 2

How to identify HCl and SO²

Answer 2

Colourless, pungent and turns blue litmus red

HCl -> produces white fumes with ammonia vapours

SO² -> Decolourises purple colour of acidified potassium permanganate
Changes color of acidified potassium dichromate(VI) from orange to green.

Question 3

What is the confirmatory test for oxygen gas?

Answer 3

Relights a glowing wooden splinter.

Question 4

What is the confirmatory test for hydrogen gas?

Answer 4

Produces a ‘pop’ sound with a lighted wooden splinter.

Question 5

How do you test for carbon dioxide gas?

Answer 5

Turns limewater cloudy.
Damp blue litmus to red

Question 6

What is the confirmatory test for ammonia gas?

Answer 6

Colourless pungent smell

Turns moist red litmus paper blue.

Produces thick white fumes with hydrogen chloride gas.

Question 7

How can you confirm the presence of chlorine gas?

Answer 7

Bleaches moist red litmus paper.

Greenish yellow gas

Turns moist blue litmus paper red, then bleaches it.

Question 8

Which gas turns moist blue litmus paper red and is associated with brown fumes?

Answer 8

Nitrogen dioxide gas.

Question 9

How do you confirm the presence of sulphur dioxide gas?

Answer 9

Decolorises an acidified potassium manganate(VII) solution.

Question 10

What happens to

white anhydrous copper(II) sulphate
blue cobalt(II) chloride paper

when exposed to water vapor?

Answer 10

It turns blue.

It turns pink

Question 11

What is the color change when heating zinc nitrate (ZnNO3)2?

Answer 11

Turns yellow when hot and white when cool.

Question 12

What happens to iron² and iron³ nitrate upon heating?

Answer 12

No change
Green
Brown

Question 13

What nitrate salts are white before and after heating

Answer 13

K
Na
Ca
Mg
Al
Sn

Question 14

Effects of heat on Pb(NO3)2

Answer 14

Brown when hot
White when cool

Question 15

Effects of heat on Cu(NO3)2

Answer 15

Changes from blue to black

Question 16

Nitrate salts upon heat
Formed metal, nitrogen dioxide gas and oxygen gas

Answer 16

Hg²
Ag
Au³

Question 17

Effects of heat on Hg(NO3)2 and Ag(NO3)

Answer 17

White to grey
White to shiny grey

Question 18

Effects of heat on gold nitrate

Answer 18

White to Golden Yellow

Question 19

Carbonate/ Nitrate Salts
That do not decompose when heated

Answer 19

K
Na

Question 20

Carbonate/ Nitrate salts
Formed metal oxide and carbon dioxide gas

Answer 20

1. Ca
2. Mg
3. Al
4. Zn
5. Fe²
6. Fe³
7. Sn
8. Pb
9. Cu
10. Hg (not included on nitrate)

Question 21

Carbonate/ Nitrate Salts
Formed a metal, carbon dioxide gas and oxygen gas

Answer 21

Ag
Au
(Nt + Hg(

Question 22

Carbonate/ Nitrate Salts
That are white before and after heating

Answer 22

Ca
Mg
Al
Sn

Question 23

Colour of zinc carbonate / nitrate when heated

Answer 23

White before heating
White when cooled
Yellow when heated

Question 24

Colour of Iron²/³ carbonate / nitrate when heated

Answer 24

Green and brown before and after

Question 25

Colour of Lead carbonate and nitrate when heated

Answer 25

White before heating Yellow when cooled Brown when hot

Question 26

Copper carbonate/nitrate before and after heat

Answer 26

Green Blue Black after heated

Question 27

Mercury(Hg) carbonate and nitrate during heating

Answer 27

White before, silver after

Question 28

Silver and gold carbonate/nitrate during heating

Answer 28

Silver white to shiny grey Gold white to golden yellow

Question 29

Colour of salt in solid state (White) Colour of salt in solution (Colourless)

Answer 29

Ca Mg Al Pb NH⁴

Question 30

Colour of salt in solid state Colour of salt in solution (Blue)

Answer 30

CuSO⁴, Cu(NO³)²

Question 31

Colour of salt in solid state (Green) Colour of salt in solution (Blue)

Answer 31

CuCl²

Question 32

Colour of salt in solid state Colour of salt in solution (Green)

Answer 32

Salts of Fe²

Question 33

Colour of salt in solid state (Brain) Colour of salt in solution (Yellow)

Answer 33

Fe³