Inorganic tests

Question 1

Oxygen

Answer 1

Relights glowing splint

Question 2

Hydrogen

Answer 2

Squeaky pop

-burning splint near top of test tube with hydrogen
-squeaky pop heard

Question 3

Test for metal nitrates

Answer 3

• Heat and either test for oxygen given off with relighting of a glowing splint

OR

-Observe brown nitrogen dioxide gas being given off

Question 4

Test for metal carbonates

Answer 4

-Heat Metal carbonate in test tube
(OR react with strong acid )
-use a delivery tube to bubble gas ( CO2 gas) given off into limewater

Positive result : limewater turns cloudy

Question 5

Metal carbonate/ nitrates thermal stability

Answer 5

• Higher the charge density of the cation
• the greater the polarising power
• the more the anion is polarised
  -the more the bonds in the anion (N-O or C-O ) are weakened —> NAME BOND

Question 6

tests for acids and bases

Answer 6

-litmus paper
-Turns red in presence of acid
-Turns blue in presence of base (remember BBBase BBBlue)

Question 7

Test for NH4+ ions

Answer 7

-Add NaOH (aq) to the solution
-Ammonia gas should be released
-Turning litmus paper blue
-and giving it pungent smell

Question 8

Test for SO4 2- ions

Answer 8

• Add acidified BaCl2 solution (DO NOT USE H2SO4 —> gives false positive)

-White precipitate of BaSO4 should form

-BaCl2 acidified with HCl to remove impurities (HCl reacts with impurities)