QA

Question 1

Test for hydrogen gas and observation

Answer 1

1. Place lighted splint -> mouth of test tube
   R: lighted splint extinguish w/ pop sound

Do this test when
- wooden splint
- any reactive metal given

Question 2

Test for carbon dioxide and observation

Answer 2

1. bubble gas -> limewater
   R: white ppt formed -> limewater

Do this test when:
- limewater/aqueous calcium hydroxide given
- carbonate given

Question 3

co2 test add test reagent in excess, what is the result?

Answer 3

1. add limewater in excess
   R: white ppt. dissolves, clear soln.

Do this test to:
- confirm it is co2 and not something else

Question 4

Test for oxygen gas

Answer 4

1. Place glowing splint -> mouth of test tube
   R: rekindles glowing splint

Question 5

Limewater chemical name

Answer 5

aqueous calcium hydroxide

Question 6

what is Qualitative Analysis for?

Answer 6

identify unknown salt

LINK
all salts have cation + anion

Question 7

2 possible water vapour tests

Answer 7

first
1. place cobalt(II) chloride paper -> mouth of test tube
R: Blue cobalt chloride paper -> pink

second
1. drop few droplets of liquid -> dehydrated CuSo4 (II)
R: White CuSo4 (II) turn blue

Do not use litmus paper/universal indicator

Question 8

Test for chlorine gas and result

Answer 8

blue litmus paper
Process: put damp blue litmus paper near mouth test tube
R: turns damp blue litmus paper red, bleaches

red litmus paper
Process: put damp red litmus paper near mouth test tube
R: bleaches damp red litmus paper

Question 9

Test for sulfur dioxide gas and result

Answer 9

R: turn aqueous acidified potassium maganate (VII) purple -> colourless

Question 10

test for aqueous ammonia

Answer 10

R: turns damp red litmus paper blue

use red litmus paper to differentiate between aq ammonia and chlorine

Question 11

is chloride and chlorine the same thing? what is the similarity/difference?

Answer 11

Chlorine
- gas
- Cl₂

Chloride
- anion, only present in salt!
- Cl-

Question 12

list all acidic, alkaline neutral gases tested in QA

Answer 12

acidic
- cl2
- co2
- sulfuric (so2)
alkaline
- nh3
neutral
- h2
- o2

P.S.: nitrogen is neutral gas that need know but no test in QA

Question 13

2 testers for cation

Answer 13

aqueous sodium hydroxide
aqueous ammonia

all cations have normal vol. and excess vol. results

Question 14

zinc effect on aqueous sodium hydroxide (normal + excess)

Answer 14

normal
- white ppt.

excess
- soluble in excess -> colourless soln.

EXTRA INFO FOR LAB
(soln. appearance has change when added in excess, as white ppt. dissolves)

MEMO
- zinc
- iron(III)
- iron (II)

have same effect on both testers

Question 15

zinc effect on aqueous ammonia (normal + excess)

Answer 15

normal
- white ppt.

excess
- soluble in excess -> colourless soln.

MEMO
- zinc
- iron(III)
- iron (II)

have same effect on both testers

Question 16

effect of aq. sodium hydroxide on iron (III) (normal + excess)

Answer 16

normal
- red-brown ppt.

excess
- insoluble

MEMO
- zinc
- iron(III)
- iron (II)

have same effect on both testers

Question 17

effect of aq. ammonia on iron (III) (normal + excess)

Answer 17

normal
red-brown ppt.

excess
- insoluble

MEMO
- zinc
- iron(III)
- iron (II)

have same effect on both testers

Question 18

effect of aq. sodium hydroxide on iron (II) (norm + excess)

Answer 18

normal
green ppt.

excess
insoluble

MEMO
- zinc
- iron(III)
- iron (II)

have same effect on both testers

Question 19

effect of aq. ammonia on iron (II) (norm + excess)

Answer 19

normal
green ppt.

excess
insoluble

Question 20

effect of aq. sodium hydroxide on copper(II) (norm + excess)

Answer 20

norm
light blue ppt.

excess
insoluble

Question 21

effect of aq. ammonia on copper (II) (norm + excess)

Answer 21

norm
light blue ppt.
excess
soluble, give dark blue solution

ppt. dissolves to give dark blu soln. when reagent in excess

Question 22

effect of aq. sodium hydroxide on calcium

Answer 22

norm
white ppt.
excess
insol

Question 23

effect of aq. ammonia on calcium

Answer 23

norm, excess
no ppt.

Question 24

effect of aq. sodium hydroxide on ammonium

Answer 24

norm
ammonia produced, warming

excess
NIL

Question 25

effect of aq. ammonia on ammonium

Answer 25

NIL

Question 26

effect of aq. sodium hydroxide on aluminium ## Footnote **SAME AS LEAD(II)**

Answer 26

**norm** white ppt. **excess** soluble -> colourless soln. ## Footnote all **soluble** white ppt gives colourless soln.

Question 27

effect of aq. ammonia on aluminium ## Footnote **SAME AS LEAD(II)**

Answer 27

**norm** white ppt. **excess** insoluble

Question 28

# anion test for sulfate

Answer 28

1. acidify w/ dilute nitric acid add aq. barium nitrate R: white ppt. ## Footnote anions have no excess reactant result, do not share reactants unlike cation test

Question 29

# anion test for nitrate

Answer 29

1. add aq. sodium hydroxide 2. add alumnium foil 3. warm carefully R: ammonia produced

Question 30

# anion test for iodide

Answer 30

1. acidify soln. w/ dilute nitric acid 2. add aq. barium nitrate R: yellow ppt.

Question 31

# anion test for chloride

Answer 31

1. acidify w/ dilute nitric acid 2. add aq. silver nitrate R: white ppt.

Question 32

test for carbonate

Answer 32

1. add dilute acid R: efferverscence, carbon dioxide produced

Question 33

# all are soluble when any salt + sodium hydroxide/ammonia, form which salt?

Answer 33

____ hydroxide

Question 34

which acid to test for carbonate?

Answer 34

nitric acid ## Footnote **IMPORTANT** For all cations, test for carbonate first by adding nitric acid R: efferverscence

Question 35

which substance dont form base (oxide/hydroxide)

Answer 35

gold ## Footnote rest forms oxide

Question 36

colour of lead(II) iodide ppt.

Answer 36

**yellow**

Question 37

wat if u cancel everything in ionic eqn?

Answer 37

You're likely wrong. Recheck But if it really really really is, then its **NO REACTION OCCURED**

Question 38

colour of 1. CuCo3 2. CuO 3. Cu metal 4. rest of Cu(II) **COMPOUNDS**

Answer 38

1. copper carbonate -> green 2. copper oxide -> black 3. copper metal -> brown 4. all other copper coumpounds -> blue

Question 39

another way to craft ionic eqn. for BaSo4 other than cancelling spectator ions

Answer 39

Ba+ (cation) + So42- (anion) -> BaSo4 ## Footnote Cation and Anion split, put **CHARGES** must **BALANCE**, must follow: - Metal as an **element** exists on it's own - Cl2, e.g. as an **elemtent** is diatomic

Question 40

lime water ppt name

Answer 40

CaCo3 Calcium Carbonate