The formula of an acid is ${\mathrm{HXO}}_2.$ The mass of 0.0242 moles of the acid is 1.657 g.
The atomic weight of X is:

1.	35.5	2.	28.1
3.	128	4.	19.0

The sulphate of the metal M contains 9.87% of M. This sulphate is isomorphous with ${\mathrm{ZnSO}}_4.7{\mathrm{H}}_2\mathrm{O}$. The atomic weight of M is:

1.  40.3

2.  36.3

3.  24.3

4.  11.3

Sulphur burns according to the reaction

 $\frac{1}{8}{\mathrm{S}}_8\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$ $\stackrel{}{\to }$ ${\mathrm{SO}}_2\left(\mathrm{g}\right)$
What volume of air, at 1 atm and 273 K, containing 21%  oxygen by volume is required to completely burn sulphur $\left({\mathrm{S}}_8\right)$ present in 200 g of the sample?
(This sample contains 20% inert material which does not burn)

1.  23.52 litre

2.  320 litre

3.  112 litre

4.  533.33 litre

100 mL of H₂SO₄ solution having molarity 1 M and density 1.5 g mL⁻¹ is mixed with 400 mL water.
If the density of the final solution is 1.25 g mL⁻¹, calculate the molarity of the final H₂SO₄ solution.

Which of the following combinations illustrates the law of reciprocal proportions?
1. \(\mathrm{N}_2 \mathrm{O}_3, \mathrm{~N}_2 \mathrm{O}_4, \mathrm{~N}_2 \mathrm{O}_5 \)
2. \(\mathrm{NaCl}, \mathrm{NaBr}, \mathrm{Nal}\)
3. \(\mathrm{CS}_2, \mathrm{CO}_2, \mathrm{SO}_2 \)
4. \(\mathrm{PH}_3, \mathrm{P}_2 \mathrm{O}_3, \mathrm{P}_2 \mathrm{O}_5\)

Which of the following is dependent on temperature?

A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$. The evolved gaseous mixture is passed through KOH pellets.

Weight (in g) of the remaining product at STP will be:

1. 1.4

2. 3.0

3. 2.8

4. 4.4

20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g of magnesium oxide.
The percentage purity of magnesium carbonate in the sample is: 
(Atomic weight of Mg=24)