The oxide of metal contains 40% by mass of oxygen. The percentage of chlorine in the chloride of the metal is

1. 84.7

2. 74.7

3. 64.7

4. 44.7

What volume of ${\mathrm{O}}_2\left(\mathrm{g}\right)$ measured at 1 atm and 273 K will be formed by the action of 100 mL of 0.5 N KMnO₄ on hydrogen peroxide in an acid solution?

The skeleton equation for the reaction is

${\mathrm{KMnO}}_4+{\mathrm{H}}_2{\mathrm{SO}}_4+{\mathrm{H}}_2{\mathrm{O}}_2<mspace\; width="1em"></mspace>$$\to {\mathrm{K}}_2{\mathrm{SO}}_4+{\mathrm{MnSO}}_4+{\mathrm{O}}_2+{\mathrm{H}}_2\mathrm{O}$

1.  0.12 litre

2.  0.028 litre

3.  0.56 litre

4.  1.12 litre

Read the following statements (S) and Explanation (E). Choose the correct answers from the codes (1), (2), (3) and (4):

S : An element may have variable equivalent mass.

E : Such elements should possess variable valency. 

1.  S is correct but E is wrong
2.  S is wrong but E is correct
3.  Both S and E are correct and E is correct explanation of S
4.  Both S and E are correct but E is not correct explanation of S