tests for gases , tests for cations

test for chlorine

bleaches damp litmus paper turning it white

may be red for a second as solution is acidic

test for oxygen

if you put a glowing splint inside a test tube with oxygen the splint should relight

test for carbon dioxide

bubbling co2 through a aqueous solution of calcium hydroxide(lime water) will turn the solution cloudy

test for hydrogen

if you hold a lit splint at the open end of a test tube a squeaky pop sound should be made

test for sulphates

add a couple drops of hcl then a couple drops of barium chloride a white precipitate should be formed

test for a carbonate

place a drop of dilute acid into a test tube connect this test tube to a test tube of limewater if it turns cloudy a carbonate is present

how to test for any halide

add a drop of dilute nitric acid followed up by a couple of drops of silver nitrate solution

positive result for chloride

white precipitate of silver chloride

positive result of bromide

gives of a cream precipitate of silver bromide

positive test for an iodide

gives off a yellow precipitate of silver iodide

flame test for lithium

Li+ - burns with a crimson flame

flame test for sodium ions

NA+ - burns with a yellow flame

flame test potassium ions

K+ - burn with a lilac flame

flame test for calcium ions

Ca2+ - orange-red flame

flame test for copper

Cu2+- burn with a green flame

how to perform a flame test

clean a platinum wire loop by dipping it in some dilute HCL then hold the wire over a blue flame from a bunsen burner until it burns without any colour. Lastly dip the loop into the sample you want to test and put it back over the flame, then record the colour of the flame

many metals form a coloured precipitate with NAOH

what happens when a solution with calcium in it has sodium hydroxide added to it

forms a white precipitate

what happens when a solution with copper(11) in it has sodium hydroxide added to it

forms a blue precipitate

what happens when a solution with iron(II) in it has sodium hydroxide added to it

forms a green precipitate

what happens when a solution with iron(III) in it has sodium hydroxide added to it

forms a brown precipitate

what happens when a solution with aluminium in it has sodium hydroxide added to it

forms a white precipitate at first but then turns colourless as it redissolves with excess NAOH

what happens when a solution with magnesium in it has sodium hydroxide added to it

forms a white precipitate