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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