how do you test for an aluminium cation?
aqueous sodium hydroxide: white ppt. formed, soluble in excess to form a colourless solution
aqueous ammonia: white ppt. formed, insoluble in excess
how do you test for a zinc cation?
aqueous sodium hydroxide: white ppt. formed, soluble in excess to form a colourless solution
aqueous ammonia: white ppt. formed, soluble in excess to form a colourless solution
how do you test for a calcium cation?
aqueous sodium hydroxide: white ppt. formed, insoluble in excess
aqueous ammonia: no ppt. formed
how do you test for a copper(II) cation?
aqueous sodium hydroxide: blue ppt. formed, insoluble in excess
aqueous ammonia: blue ppt. formed, soluble in excess to form a dark blue solution
how do you test for a iron(II) cation?
aqueous sodium hydroxide/ammonia: green ppt. formed, insoluble in excess
*forms red-brown ppt. when on standing in air as it oxidises
how do you test for a iron(III) cation?
aqueous sodium hydroxide/ammonia: red-brown ppt. formed, insoluble in excess
how do you test for an ammonium cation?
aqueous sodium hydroxide: no ppt. formed, colourless pungent gas evolves upon heating which turns damp red litmus paper blue
how do you test for a carbonate anion?
add any dilute acid; effervescence of a colourless and odourless gas which forms white ppt. in limewater
how do you test for a sulfate anion?
add dilute nitric acid and aqueous barium nitrate; white ppt. forms (barium sulfate)
how do you test for a chloride anion?
add dilute nitric acid and aqueous silver nitrate; white ppt. forms (silver chloride)
how do you test for an iodide anion?
add dilute nitric acid and aqueous silver nitrate; yellow ppt. formed (silver iodide)
how do you test for a nitrate anion?
add aqueous sodium hydroxide and a small piece of aluminium foil before warming the mixture; effervescence of a colourless and pungent gas, gas evolved turns damp red litmus paper blue
how do you test and identify carbon dioxide?
- colourless, odourless
- bubble into limewater
- white ppt. forms (calcium carbonate)
how do you test and identify ammonia gas?
- colourless, pungent
- use damp red litmus paper
- turns the litmus paper blue
how do you test and identify hydrogen gas?
- colourless, odourless
- use a lighted splint
- extinguishes lighted splint with a ‘pop’ sound
how do you test and identify oxygen gas?
- colourless, odourless
- use a glowing splint
- relights glowing splint
how do you test and identify sulfur dioxide?
- colourless, pungent
- use aqueous acidified potassium manganate(VII) on filter paper
- turns from purple to colourless
how do you test and identify chlorine gas?
- greenish-yellow, pungent
- use damp blue litmus paper
- turns litmus paper red, then bleaches it
