Experiment 7: Group IV Cations (Alkaline Earth Group)ReagentBa2+Sr2+Ca2+Mg2+

Flame testyellowish greencrimson redbrick or dull redcolorless

(NH4)2CO3, NH4Cl, C2H5OHBaCO3white pptSrCO3white pptCaCO3white pptAbsence of alcohol - MgCO2Mg(OH)2Presence of alcohol -MgCO2(NH4)2CO3.4H2O

K2CrO4

a.)CH3COOHBaCrO4yellowpptinsolubleSrCrO4yellowpptinsolubleCaCrO4sol. ppt in the presence of alc.insolublesoluble

insoluble

K2C2O4

a.)CH3COOHBaC2O4white pptsolubleSrCO4white pptsolubleCaC2O4white pptinsolublesoluble

soluble

(NH4)2SO4

a.) HClBaSO4white pptinsolubleSrSO4white pptsol. in boiling HClCaSO4ppt in the presence of alcoholsolublevery soluble

very soluble

Na2HPO4

NH4OHBa3(PO4)2

white amorphous pptSr3(PO4)2

white amorphous pptCa3(PO4)2

white amorphous pptMg(NH4)PO4

white crystalline ppt