A bottle of ${\mathrm{H}}_3{\mathrm{PO}}_4$ solution contains 70% (w/w) acid. If the density of the solution is 1.54 g ${\mathrm{cm}}^{-3}$, the volume of the ${\mathrm{H}}_3{\mathrm{PO}}_4$ solution required to prepare 1 L of 1 N solution is

1.  90mL

2.  45 mL

3.  30 mL

4.  23 mL

The density of a 2 M aqueous solution of NaOH is 1.28 g/$c{m}^3$. The molality of the solution is: 
[molecular mass of NaOH = 40 g mol^-1]

The molality of pure water is: 

1. 1 m

2. 18 m

3. 55.5 m

4. None of the above

10 g of a silver coin when dissolved completely in
excess of conc. HNO${}_3$ gives 8.5 g of silver nitrate.
The percentage purity of the coin is

1. 25%

2. 54%

3. 67%

4. 100%

The hydrated salt Na₂SO₄.nH₂O, undergoes 55% loss in weight on heating and becomes anhydrous. The value of n will be -

1. 5

2. 3

3. 7

4. 10

At 100 ºC and 1 atm, if the density of liquid water is 1.0 g cm^–3 and that of water vapor is 0.0006 g cm^-3, then the volume occupied by water molecules in 1 litre of steam at that temperature will be:

ln a closed vessel, 50 ml of $A_2{B}_3$ completely reacts with 200 ml of C₂ according to the following equation:

$2A_2{B}_3\left(g\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>5C_2\left(g\right)\to <mspace\; width="1em"></mspace>3C_3{B}_2\left(g\right)+C{A}_4\left(g\right)$

What will be the composition of the gaseous mixture in the system?

1. 100 ml $C_2,<mspace\; width="1em"></mspace>50<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C_3{B}_2,50<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C{A}_4$

2. 25 ml $C_2,<mspace\; width="1em"></mspace>75<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>C_3{B}_{\mathrm{2,}}<mspace\; width="1em"></mspace>25<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C{A}_4$

3. 75 ml $C_2,<mspace\; width="1em"></mspace>75<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C_3{B}_{2,<mspace\; width="1em"></mspace>}25<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C{A}_4$

4. 10 ml $C_2,<mspace\; width="1em"></mspace>25<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C_3{B}_{2,<mspace\; width="1em"></mspace>}100<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C{A}_4$

Calculate the mass of $\mathrm{CaO}$ required to remove the hardness of ${10}^6$ litre of water containing 1.62 g of calcium bicarbonate per litre.

1. 5.6*10^-6 

2. 5.6*10^5

3. 4.8*10^9

4. 1.2*10^-4

0.5 g of fuming ${\mathrm{H}}_2{\mathrm{SO}}_4$ (oleum) is diluted with water. The solution requires 26.7 mL of 0.4 N $\mathrm{NaOH}$ for complete neutralization. Find the % of free ${\mathrm{SO}}_3$ in the sample of oleum. Also report % of oleum solution.

1. 104.68 %

2. 98 %

3. 106.13%

4. 56 %