QA Flashcards
QA tests. R: represents the thing testing positive
Test for hydrogen gas and observation
- Place lighted splint -> mouth of test tube
R: lighted splint extinguish w/ pop sound
Do this test when
- wooden splint
- any reactive metal given
Test for carbon dioxide and observation
- bubble gas -> limewater
R: white ppt formed -> limewater
Do this test when:
- limewater/aqueous calcium hydroxide given
- carbonate given
co2 test add test reagent in excess, what is the result?
-
add limewater in excess
R: white ppt. dissolves, clear soln.
Do this test to:
- confirm it is co2 and not something else
Test for oxygen gas
- Place glowing splint -> mouth of test tube
R: rekindles glowing splint
Limewater chemical name
aqueous calcium hydroxide
what is Qualitative Analysis for?
identify unknown salt
LINK
all salts have cation + anion
2 possible water vapour tests
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
Test for chlorine gas and result
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
Test for sulfur dioxide gas and result
R: turn aqueous acidified potassium maganate (VII) purple -> colourless
test for aqueous ammonia
R: turns damp red litmus paper blue
use red litmus paper to differentiate between aq ammonia and chlorine
is chloride and chlorine the same thing? what is the similarity/difference?
Chlorine
- gas
- Cl₂
Chloride
- anion, only present in salt!
- Cl-
list all acidic, alkaline neutral gases tested in QA
acidic
- cl2
- co2
- sulfuric (so2)
alkaline
- nh3
neutral
- h2
- o2
P.S.: nitrogen is neutral gas that need know but no test in QA
2 testers for cation
aqueous sodium hydroxide
aqueous ammonia
all cations have normal vol. and excess vol. results
zinc effect on aqueous sodium hydroxide (normal + excess)
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
zinc effect on aqueous ammonia (normal + excess)
normal
- white ppt.
excess
- soluble in excess -> colourless soln.
MEMO
- zinc
- iron(III)
- iron (II)
have same effect on both testers
effect of aq. sodium hydroxide on iron (III) (normal + excess)
normal
- red-brown ppt.
excess
- insoluble
MEMO
- zinc
- iron(III)
- iron (II)
have same effect on both testers
effect of aq. ammonia on iron (III) (normal + excess)
normal
red-brown ppt.
excess
- insoluble
MEMO
- zinc
- iron(III)
- iron (II)
have same effect on both testers
effect of aq. sodium hydroxide on iron (II) (norm + excess)
normal
green ppt.
excess
insoluble
MEMO
- zinc
- iron(III)
- iron (II)
have same effect on both testers
effect of aq. ammonia on iron (II) (norm + excess)
normal
green ppt.
excess
insoluble
effect of aq. sodium hydroxide on copper(II) (norm + excess)
norm
light blue ppt.
excess
insoluble
effect of aq. ammonia on copper (II) (norm + excess)
norm
light blue ppt.
excess
soluble, give dark blue solution
ppt. dissolves to give dark blu soln. when reagent in excess
effect of aq. sodium hydroxide on calcium
norm
white ppt.
excess
insol
effect of aq. ammonia on calcium
norm, excess
no ppt.
effect of aq. sodium hydroxide on ammonium
norm
ammonia produced, warming
excess
NIL
effect of aq. ammonia on ammonium
NIL
effect of aq. sodium hydroxide on aluminium
SAME AS LEAD(II)
norm
white ppt.
excess
soluble -> colourless soln.
all soluble white ppt gives colourless soln.
effect of aq. ammonia on aluminium
SAME AS LEAD(II)
norm
white ppt.
excess
insoluble
anion
test for sulfate
- acidify w/ dilute nitric acid add aq. barium nitrate
R: white ppt.
anions have no excess reactant result, do not share reactants unlike cation test
anion
test for nitrate
- add aq. sodium hydroxide
- add alumnium foil
- warm carefully
R: ammonia produced
anion
test for iodide
- acidify soln. w/ dilute nitric acid
- add aq. barium nitrate
R: yellow ppt.
anion
test for chloride
- acidify w/ dilute nitric acid
- add aq. silver nitrate
R: white ppt.
test for carbonate
- add dilute acid
R: efferverscence, carbon dioxide produced
all are soluble
when any salt + sodium hydroxide/ammonia, form which salt?
____ hydroxide
which acid to test for carbonate?
nitric acid
IMPORTANT
For all cations, test for carbonate first by adding nitric acid
R: efferverscence
which substance dont form base (oxide/hydroxide)
gold
rest forms oxide
colour of lead(II) iodide ppt.
yellow
wat if u cancel everything in ionic eqn?
You’re likely wrong. Recheck
But if it really really really is, then its NO REACTION OCCURED
colour of
1. CuCo3
2. CuO
3. Cu metal
4. rest of Cu(II) COMPOUNDS
- copper carbonate -> green
- copper oxide -> black
- copper metal -> brown
- all other copper coumpounds -> blue
another way to craft ionic eqn. for BaSo4 other than cancelling spectator ions
Ba+ (cation) + So42- (anion) -> BaSo4
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
lime water ppt name
CaCo3
Calcium Carbonate
