Principles Related to Practical Chemistry

The oxidation number of iron in the compound formed during brown ring test for NO3- ion is .

Yellow compound of lead chromate gets dissolved on treatment with hot NaOH solution. The product of lead formed is a :

1. Tetraanionic complex with coordination number six
2. Neutral complex with coordination number four
3. Dianionic complex with coordination number six
4. Dianionic complex with coordination number four

NaCl reacts with conc. H2SO4 and K2Cr2O7 to give reddish fumes (B), which react with NaOH to give yellow solution (C). (B) and (C) respectively are ;

1. CrO2Cl2, Na2CrO4
2. Na2CrO4, CrO2Cl2
3. CrO2Cl2, KHSO4
4. CrO2Cl2, Na2Cr2O7

The technique used for purification of steam volatile water immiscible substances is :

1. Fractional distillation
2. Distillation
3. Fractional distillation under reduced pressure
4. Steam distillation

Phenolic group can be identified by a positive:

1. Tollen's test
2. Phthalein dye test
3. Carbylamine test
4. Lucas test