Question

please answer the questions

Answer 1

1) As surface area increases on pouring hot tea in saucer from the cup and the rate of loss of heat is directly proportional to surface area of the radiating surface, so the tea will cool faster in the saucer.
2) Oxidation refers to losing of electrons while reduction refers to the gaining of electrons. The reactions in which oxidation and reduction takes place simultaneously are referred to redox reaction. For e.g.

CuO + H2 →  Cu + H2O

Here copper oxide is reduced and thus acts as oxidizing agent.H2 is oxidized and acts as reducing agent.

There are reactions in which oxidation and reduction of same compound results. Such reactions are called disproportionation reaction. For e.g. on heating potassium chlorate we get

2KClO3 → 2KCl + 3O2

2H2O2 → 2H2O + O2
3) The solution A is the strongest acid as the pH value is 2