Analysis (testing for positive ions)

Barium goes GREEN

Sodium goes YELLOW

Calcium goes ORANGE

Potassium goes PURPLE

Lithium goes RED

Cu 2+ has a Blue Precipitate ( Cu 2+ (aq) + 2OH- (aq) = Cu(OH)2 (s) )

Fe 2+ has a Green Precipitate (goes orange in air)

Fe 3+ has a Orange Precipitate ( Fe 3+ (aq) + OH- (aq) = Fe(OH)3 (s) )

Al 3+ has a White Precipitate ( in excess NaOH, Al precipitate dissolves)

Mg 2+ has a White Precipitate

Ca 2+ has a White Precipitate

NH4+ + NaOH(warmed) = NH3

Test for NH3 is the smell and using red litmus paper goes blue as ammonium is alkaline.