Test Tubes Flashcards
Test for alkene
Reagent
Observation
Reason for observation
Bromine water
Colourless
Br2 attaches to alkenes
Test for primary , secondary alcohol and aldehyde
Reagent
Observation
Reason for observation
Acidified pottasium dicromate
Oraange to green
Cr is reduced
Alchocol and aldehyde oxidsied
Aldeyhde test
Reagents
Observations
Reason for observations
Tollens reagent
Silver mirror
Aldehyde oxidised
Fehlings reagent
Brick red precipitate
Aldehyde oxidised
Carboxylic acid / any acid test
Reagent
Observation
Reason for observation
Sodium carbonate
Effeservence
CO2 formed
Test for Ba2+
Reagent
observation
Equation
H2SO4
White ppt
Ba2+ + SO42- ———-> BaSO4
Test for SO42-
Reagent
observation
Equation
Acidified BaCl2
White ppt
Ba2+ + SO42- ———-> BaSO4
Test for Mg2+
Reagent
observation
Equation
NaOH
White ppt
Mg2+ + 2OH- ———-> Mg(OH)2
Test for OH-
Reagent
observation
Equation
MgCl2
White ppt
Mg2+ + 2OH- ———-> Mg(OH)2
Test for Cl-
Reagent
observation
Equation
Acidified HNO3 & AgNO3
White ppt
Ag+ + Cl- ———-> AgCl
Test for Br-
Reagent
observation
Equation
Acidified HNO3 & AgNO3
Cream ppt
Ag+ + Br- ———->AgBr
Test for I-
Reagent
observation
Equation
Acidified HNO3 & AgNO3
ywellow ppt
Ag+ + I+ ——-> AgI
Test for AgCl
Reagent
observation
Equation
Dillute NH3
AgCl ppt dissolves
AgCl + 2NH3 ———> [Ag(NH3)2]2 + Cl-
Test for AgBr
Reagent
observation
Equation
Concentrated NH3
AgBr ppt. dissolves
AgBr(s) + 2NH3(aq) → [Ag(NH3)2]+(aq) + Br−(aq)
Test for NH4+
Reagent
observation
Equation
NaOH & heat
Gas released turns red litmus paper blue
NH4+ + OH- ——-> NH3 + H2O
Test for Fe2+
NaOH
Green ppt —-> browm on standing air
Formation of [Fe(H2O)4(OH)2]