Which of the following setups is/are most appropriate for the evolution of hydrogen gas and its identification?

1. I
2. IV
3. III
4. Only II

The oxides and hydroxides of which metal are amphoteric?

1. Sodium
2. Zinc
3. Iron
4. Magnesium

Which of the following electrolyte is used in the process of nickle plating?

1. Silver nitrate
2. Potassium argentocyanide
3. Nickle ammonium sulphate
4. Carbon rods

The empirical formula of hexane is

1. C₃H₇
2. C₆H₁₄
3. C₃H₈
4. C₄H₁₂