Study the experimental set-up shown in given figure and choose the correct option from the following:

The pair(s) which will show displacement reaction is/are

(i) NaCl solution and copper metal

(ii) AgNO₃ solution and copper metal

(iii) Al₂(SO₄)₃ solution and magnesium metal

(iv) ZnSO₄ solution and iron metal

1. (ii) only
2. (ii) and (iii)
3. (iii) and (iv)
4. (i) and (ii)

Consider the pH value of the following acidic samples :

The decreasing order of their H⁺ ion concentration is

1. 3 > 4 > 1 > 2
2. 2 > 1 > 3 > 4
3. 2 > 1 > 4 > 3
4. 3 > 4 > 2 > 1

Which of the following salts do not have the water of crystallisation?

(i) Bleaching Powder

(ii) Plaster of Paris

(iii) Washing soda

(iv) Baking soda

1. (ii) and (iv)
2. (i) and (iii)
3. (ii) and (iii)
4. (i) and (iv)