qualitative analysis: cation tests Flashcards
NH4+ (ammonium) tested with NaOH
no ppt formed. on heating, gas evolved turns moist red litmus paper blue. the gas is NH3
Ca2+ tested with NaOH
a white ppt formed, insoluble in excess aqueous NaOH
Ca2+ tested with NH3
no ppt is formed
Al3+ tested with NaOH
a white ppt formed. the ppt is soluble in excess aqueous NaOH to form a colourless solution
Al3+ tested with NH3
a white ppt formed, insoluble in excess aqueous NH3
Pb2+ tested with NaOH
a white ppt formed. the ppt is soluble in excess aqueous NaOH to form a colourless solution
Pb2+ tested with NH3
a white ppt formed, insoluble in excess aqueous NH3
Zn2+ tested with NaOH
a white ppt formed. the ppt is soluble in excess aqueous NaOH to form a colourless solution
Zn2+ tested with NH3
a white ppt formed. the ppt is soluble in excess aqueous NH3 to form a colourless solution
Cu2+ tested with NaOH
a light blue ppt formed, insoluble in excess aqueous NaOH
Cu2+ tested with NH3
a blue ppt formed. the ppt is soluble in excess aqueous NH3 to form a dark blue solution
Fe2+ tested with NaOH
a green ppt formed, insoluble in excess aqueous NaOH
Fe2+ tested with NH3
a green ppt is formed, insoluble in excess aqueous NH3
Fe3+ tested with NaOH
a reddish-brown ppt formed, insoluble in excess aqueous NaOH
Fe3+ tested with NH3
a reddish-brown ppt formed, insoluble in excess aqueous NH3