Qualitative testing

Question 1

What is the test for carbonate ions?

Answer 1

• add dilute HNO3 to the unknown solution
• If effervescence is seen, test with limewater
• if limewater is cloudy, CO3 is present

Question 2

What is the equation of nitric acid and sodium carbonate?

Answer 2

Na2Co3 + 2HNo3 = 2Nano3 + H20 + Co2

Question 3

What is the test for sulfate ions?

Answer 3

• Add barium nitrate to your unknown solution
• if a white precipitate forms then sulfate ions are present
• This white precipitate is barium sulfate

Question 4

What is the ionic equation for the sulfate test?

Answer 4

Ba 2+(aq) + So4 2(aq)- = Baso4(s)

Question 5

What is the test for halides?

Answer 5

• Add silver nitrate to your solution
• The halide reacts with silver nitrate and forms a silver halide as a precipiate

Question 6

What color indicates chlorine is present?

Answer 6

• a white precipitate

Question 7

What colour indicates that Bromine is present?

Answer 7

• A cream precipitate

Question 8

What colour indicates that Iodine is present?

Answer 8

• A yellow precipiate

Question 9

What is the ionic equation for chlorine?

Answer 9

Cl - (aq) + Ag+ (aq) = AgCl (s)

Question 10

What is the ionic equation for bromine?

Answer 10

Br - (aq) + Ag+ (aq) = AgBr (s)

Question 11

What is the ionic equation for iodine?

Answer 11

I - (aq) + Ag+ (aq) = AgI (s)

Question 12

What silver halide is insouble

Answer 12

Iodine is insouble

Question 13

What is the test for ammonium ions?

Answer 13

• Add NaOh to an unknown solution
• This produces NH3 gas which has a pungent smell but is not qualitative (as it is insouble in water so bubbles may not be seen)
• Warm the solution to release NH3 gas
• Test using damp red litmus paper which turns blue in the presence of ammonia