Chemical Tests Flashcards
describe the test for hydrogen.
Insert a lit splint into the gas. if hydrogen is present a squeaky pop will be heard.
describe the test for oxygen.
insert glowing splint into the gas if oxygen is present the glowing splint will relight.
describe the test for carbon dioxide.
bubble gas through limewater, if CO2 is present limewater will turn milky.
describe the test for chlorine.
insert a damp piece of blue litmus paper, if chlorine is present paper will go red then bleach.
describe the test for ammonia.
insert a damp piece of red litmus paper, if ammonia is present paper will go blue.
describe how to carry out a flame test.
1) clean a platinum wire loop by dipping in some hydrochloric acid.
2) hold in the bunsen until it shows no colour.
3) then dip the loop into the sample and hold in the flame.
4) record the colour.
what colour does lithium go in a flame test?
red
what colour does sodium go in a flame test?
yellow
what colour does potassium go in a flame test?
lilac
what colour does calcium go in a flame test?
orange-red
what colour does copper go in a flame test?
blue-green
what is the test for water?
add anhydrous copper sulfate. the copper sulphate will go from white to blue if water is present.
what is the test for the purity of water?
measure the melting and boiling point. the melting point should 0 degrees, and boiling point should be 100 degrees.
what cations is the sodium hydroxide test used for?
1) copper (II) (Cu2+)
2) Iron (II) (Fe2+)
3) Iron (III) (Fe3+)
describe how to carry out a sodium hydroxide test.
1) Add 1ml of the sample solution to be tested to a test tube.
2) add sodium hydroxide
3) observe a precipitate from.
4) record the colour.
what is formed in a sodium hydroxide test for copper (II) (Cu2+)?
blue precipitate
what is formed in a sodium hydroxide test for Iron (II) (Fe2+)?
green precipitate.
what is formed in a sodium hydroxide test for Iron (III) (Fe3+)?
reddish-brown precipitate.
describe how to carry out a test for ammonium (NH4+). and the result.
1) add 1 ml of the sample solution to be tested to a test tube.
2) add sodium hydroxide
3) heat gently in a water bath
4) insert damp litmus paper into the mouth of the tube.
4) damp red litmus paper goes blue.
describe the test for anions.
add nitric acid and silver nitrate.
what is formed when testing for the anion chloride?
white precipitate
what is formed when testing for the anion bromide?
cream precipitate
what is formed when testing for the anion iodine?
yellow precipitate
describe the test for sulfate. and the result.
add hydrochloric acid followed by barium chloride. white precipitate
