practical 4- paper 1+3- group 2 and 7 tests

Question 1

test for Ba2+ including equations

Answer 1

reagent: H2SO4
observation: white precipitate of BaSO4
equation: Ba2+ + SO42- –> BaSO4

Question 2

test for SO42- including equations

Answer 2

reagent: BaCl2
observation: white ppt
Ba2+ + SO42- –> BaSO4

Question 3

test for Mg2+ including equations

Answer 3

reagent: NaOH
observation: white precipitate (formation of Mg(OH)2
Mg2+ + 2OH- –> Mg(OH)2

Question 4

test for halide ions including equations

Answer 4

reagent: AgNO3
Cl–> white ppt–> Ag+ + Cl- –> AgCl

Br- –> cream ppt–> Ag+ + Br- –> AgBr

I- –> yellow ppt–> Ag+ + I- –> AgI

Question 5

test for AgCl and AgBr

Answer 5

AgCl–> dilute NH3–> ppt dissolves
AgBr-> conc NH3–> ppt dissolves

Question 6

test for ammonium ions (NH4+)

Answer 6

NaOH and heat
gas released turns red litmus paper blue due to the formation of NH3 gas
NH4+ + OH- –> NH3 + H2O

Question 7

test for CO32-

Answer 7

any type of acid–> HNO3
effervescence due to the formation of CO2
acid + carbonate ase –> salt + water + CO2

2H+ + CO32- –> CO2 + H2O