Explain with the help of balanced equations, how precipitation reactions are used for identifying the positive radicals in three different salts, each having a different cation [positive ion].

Define the term – double decomposition – neutralization reaction with a suitable representation.

Convert :

(a) an insoluble base (b) a soluble base

to their respective soluble salts by neutralization reaction.

Supply of energy maybe required to initiate a reaction. State the different forms with a suitable example of reactions initiated by supply of energy.

Complete the statements by filling in the blank with the correct word/s :

1. Direct combination reaction of sulphur dioxide with water gives …………… [H₂SO₄/H₂SO₃/H₂S₂O₇].
2. Formation of hydrogen chloride from hydrogen and chlorine is an example of …………… [photochemical reaction / electrochemical reaction].
3. The reaction of hydrogen burning in oxygen to give a neutral liquid is an example of …………… [exothermic/endothermic] reaction.
4. The neutral gas evolved when lead nitrate undergoes thermal decomposition is …………… [nitrogen dioxide/oxygen/nitrogen].
5. The reddish brown precipitate obtained during a double decomposition - precipitation reaction between an iron salt and an alkali is …………… [iron [II] hydroxide / iron [III] hydroxide]