c12 experimental techniques

3 main ways of measuring liquids and their uses

volumetric pipettes for measuring out one set amounts of liquid accurately, measuring cylinders for larger amounts of liquids, burettes form measuring precise amounts of liquid and to measure how much liquid is needed for a reaction when there is an unknown

how are solids measured

using a balance

2 ways of measuring gas

using a gas syringe or displacing water in a measuring tube

how to determine if substance is pure using boiling points

one constant boiling point means that the substance is pure and a range of temperatures of when the substance melts means that the substance is impure

what is a chromatography used for

to determine is a substance is a mixture and if it contains a compared pure substance

lithium ions plus flame

crimson red flame

sodium ions plus flame

yellow flame

potassium ions plus flame

lilac flame

calcium ions plus flame

orange-red flames

barium plus flame

light green flame

copper plus flame

blue-green flame

how to perform a flame test

dip a nichrome wire with a loop in acid and then dap it into the substance

aluminium ions plus sodium hydroxide

white precipitate that dissolves in excess

calcium ions plus sodium hydroxide

white precipitate that doesnt dissolve in excess

chromium ions plus sodium hydroxide

green precipitate that redissolves to make green solution in excess

copper ions plus sodium hydroxide

light blue precipitate formed with no change in excess

iron(ii) ions plus sodium hydroxide

green precipitate formed with no change in excess

iron(iii) plus sodium hydroxide

red-brown precipitate with no change in excess

zinc ions plus sodium hydroxide

white precipitate formed and redissolves in excess to form clear solution

what is the chemical formula for ammonia

NH3

aluminium ions plus ammonia

white precipitate that doesn’t dissolve in excess

calcium ions plus ammonia

no visible reaction with slight white precipitate formed in excess

chromium ions plus ammonia

green precipitate that doesnt dissolve in excess

copper ions plus ammonia

light blue precipitate that dissolves to form a dark blue solution in excess

iron(ii) ions plus ammonia

green precipitate that doesnt dissolve in excess

iron(iii) ions plus ammonia

red-brown precipitate formed and doesnt dissolve in excess

zinc ions plus ammonia

white precipitate formed that dissolves to make a clear solution in excess

how do you produce ammonia

by adding sodium hydroxide to ammonium ions(NH4+)

what does ammonia do to red litmus paper

it will turn blue

what does chlorine do to red litmus paper

turns it red and then bleaches it

what does ammonia do to red litmus paper

turns it blue

chloride/bromide/iodide ions plus silver nitrate

a white/cream/yellow precipitate formed

carbonate ions plus acid

a fizz meaning carbon dioxide is forming(CO3²- + 2H+ → CO2 + H20)

nitrate ions plus sodium hydroxide and aluminium foil

nitrate ions will be reduced to form ammonia gas

how to test for sulfate ions using barium nitrate

add some dilute nitric acids to prevent precipitation reactions with the sulfate ions, then when the ions are added a white precipitate will form

how to test for sulfite ions with acid and potassium manganate

add acid to sulfite ions to form sulfur dioxide gas, then bubbling it through the potassium manganate solution the solution will turn from pink to clear