Topic 0- Fire

Question 1

what are the colours for lithium, potassium, calcium and sodium from the flame test?

Answer 1

lithium: red
potassium: lilac
calcium: brick red
sodium: yellow/orange

Question 2

how do you test for ammonium ions?

Answer 2

add aqueous sodium to the solid, or solution, under test and warm the mixture. If ammonium ions are present then a pungent-smelling gas is produced. The gas produces turns damp red litmus paper to blue.

Question 3

how do you test for metal cations?

Answer 3

add sodium hydroxide solution and the metals should change colour.
copper (II)- blue
iron (II)- green
iron (III)- brown

Question 4

how do you test for the anions: chloride, bromide and iodide?

Answer 4

add some dilute nitric acid followed by a few drops of silver nitrate solution:

• chloride ion: white precipitate
• bromide ion: cream precipitate
• iodide ion: yellow preciptate

Question 5

how do you test for sulfate ions?

Answer 5

add dilute hydrochloric acid followed by a few drops of barium chloride solution with the sulfate ions.
Result: white precipitate (of barium sulfate)

Question 6

how do you test for carbonate ions?

Answer 6

to either the solid, or an aqueous solution of the solid, under test add dilute hydrochloric (or nitric) acid
Result: bubbles of carbon dioxide gas. Test: will turn limewater milky

Question 7

what is the test for hydrogen?

Answer 7

mix with air and ignite = squeaky pop

Question 8

what is the test for oxygen?

Answer 8

inset glowing splint= splint relights

Question 9

what is the test for carbon dioxide?

Answer 9

bubble through limewater= limewater turns milky

Question 10

what is the test for ammonia?

Answer 10

damp red litmus paper= turns blue

Question 11

what is the test for chlorine?

Answer 11

damp red litmus paper= turns white