Chemistry tests

Test for carbonate ions

Add dilute HCl

Carbonates positive test

releases CO2

Sulfate ion test

Add barium chloride dissolved in HCl

why is barium chloride dissolved in HCl

Ba2+ is insoluble in water

positive sulfate test

White precipitate

Halide ion test

add nitric acid and add silver nitrate

positive halide result

AgCl white precipitate, AgBr cream precipitate, AgI yellow precipitate

Ammonium ion test

add NaOH and heat

positive ammonium test

gas will turn damp red litmus paper blue

Aldehydes test (first step)

add silver nitrate and sodium hydroxide brown precipitate will form

Aldehydes test (second test)

add ammonium solution until brown precipitate dissolves

positive test for aldehyde

silver mirror

carboxylic acid

carbonate solution pass gas through lime water

positive test for carboxylic acid

lime water goes cloudy

Phenol test (acid test)

add sodium hydroxide

phenol test (strong acid test)

add carbonate solution

positive test for phenol

test for acid will go colour less and form salt.

test for strong acid will not react negative will bubble.

Haloalkane test

add ethanol and silver nitrate and warm

positive haloalkanes

chloroalkane - white precipitate

bromoalkene - pale cream precipitate

iodoalkane - pale yellow precipitate

alkenes test and result

add bromine water. orange to colourless

Carbonyl group (C=O) test

add 2,4-DNP, sulfuric acid, water and methanol

Carbonyl positive test

aldehyde and ketone form orange precipitate

primary and secondary alcohol test

add acidified potassium dichromate.

primary and secondary alcohol positive test

slowly turns green

False positive for sulfate ions

barium chloride, barium carbonate and barium sulfide are also insoluble

false positive for halide

sulfate ions will also produce preciptate