(a) qualitative analysis of ions on a test-tube scale; processes and techniques needed to identify the following ions in an unknown compound:

              (i) anions:

• CO3 2–, by reaction with H+(aq) forming CO2(g) (see 2.1.4 c)

• SO4 2–, by precipitation with Ba2+(aq)

• Cl –, Br–, I– (see 3.1.3 g)

              (ii) cations: NH4 +, by reaction with warm NaOH(aq) forming NH3.