Chemical Reactions And Equations Test - 1

Platinum is a relatively inert metal and does not get oxidised in the air, even when heated to very high temperatures. Therefore, the emission of light by heating the platinum wire is a physical change.

In neutralisation reaction, a base reacts with an acid to form salt and water.
For example,

NaOH + HCl → NaCl + H₂O

It agrees with the format of double displacement reaction which is AB + CD → AC + BD.

Only 'B' is a valid suggestion as CuSO₄ can be safely stored in a silver vessel as no chemical reaction will occur in this case.

Silver being less reactive than copper cannot displace from its compounds.

Salt solutions of less reactive metals cannot be stored in containers made of more reactive metals as displacement reactions will take place.

Melting of ice is endothermic as energy is required to overcome the intermolecular attractions that hold the molecules together in ice.

Freezing of water is exothermic as on cooling, the molecules of water release energy to the surroundings and the intermolecular forces become more significant so that it now exists in the solid state.

Hence, both statements I and II are correct, but statement II is not the correct reason for I.

Oxidation is a chemical process and results in the formation of a new substance having properties different from those of the reactants.