Inquiry-based Chemistry Experiments

To identify 4 unlabelled white solids :3 of them are known to be sodium sulphate ,citric acid , & sodium hydrogencarbonate.1 unknown (ammonium chloride or potassium chloride)

Given : dil. & conc. HCl, dil. NaOH, lime water,AgNO3(aq) , KMnO4 / H+

(aq) , Mg ribbon ,

Pt wire , Bunser burner & common apparatus* Special items will be provided upon request

5 unlabelled compounds (3 white solids and2 colourless solutions) known to be :NaCl , Na2CO3 , citric acid, HNO3 , H2SO4

Task : To identify the compounds

Given : Cu metal 

Example 1

Add Cu

No GasBrown Gas & blue solution

H2SO4 HNO3

    

 

3 white solids & 2 colourless solutions :NaCl , Na2CO3 , citric acid, HNO3 , H2SO4 (Given : Cu metal) 

NaCl , Na2CO3 , citric acid 

Add HNO3 or H2SO4

Gas

Na2CO3

No Gas

NaCl or citric acid

Add Na2CO3

Gas No Gas

Citric acid NaCl 

4 colourless liquids are known to be :

a liquid alkane ; ethanol

a liquid alkene ; ethanoic acid

Task : To identify the 4 unlabelled compounds

Example 2

Given : solid Na2CO3 ,

acidified KMnO4 solution

liquid alkane , liquid alkene, ethanol, ethanoic acid

Given : solid Na2CO3 , KMnO4 / H+ solution

Add Na2CO3

Gas

ethanoic acid

No Gas

ethanol , alkane , alkene

Decolourize No decolourization

Add KMnO4 / H+

alkene ethanol, alkane