What is the molar mass of diacidic organic Lewis base (B), if 12 g of chloroplatinate salt $\left({\mathrm{BH}}_2{\mathrm{PtCl}}_6\right)$ on ignition produced 5 gm residue of Pt?

1.  52

2.  58

3.  88

4.  None of these

What volume of ${\mathrm{O}}_2\left(\mathrm{g}\right)$ measured at 1 atm and 273 K will be formed by 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$$\to K_{2}S{O}_4+MnS{O}_4+O_2+H_{2}O$

1.  0.12 litre

2.  0.028 litre

3.  0.56 litre

4.  1.12 litre

Cisplatin, an anticancer drug, has the molecular formula $\mathrm{Pt}{\left({\mathrm{NH}}_3\right)}_2 {\mathrm{Cl}}_2$. What is the mass (in gram) of one molecule? (Atomic weights : Pt=195, H=1.0, N=14, Cl=35.5)

1.  $4.98\times {10}^{-21}$

2.  $4.98\times {10}^{-22}$

3.  $6.55\times {10}^{-21}$

4.  $3.85\times {10}^{-22}$

The conversion of oxygen to ozone occurs to the extent of 15% only. The mass of ozone that can be prepared from 67.2 L oxygen at 1 atm and 273 K will be:

1. 14.4 gm

2. 96 gm

3. 640 gm

4. 64 gm

Average atomic mass of magnesium is 24.31 a.m.u. This magnesium is compound of 79 mole% of ${}_{24}\mathrm{Mg}$ and remaining 21 mole % of ${}_{25}\mathrm{Mg}$ and ${}_{26}\mathrm{Mg}$. Calculate mole% of ${}_{26}\mathrm{Mg}$.

1.  10

2.  11

3.  15

4.  16

Calculate the % of free ${\mathrm{SO}}_3$ in oleum (a solution of ${\mathrm{SO}}_3$ in ${\mathrm{H}}_2{\mathrm{SO}}_4$) that is labelled 109% ${\mathrm{H}}_2{\mathrm{SO}}_4$.

1. 40

2. 30

3. 50

4. None

Suppose two elements X and Y combine to form two compounds ${\mathrm{XY}}_2$ and ${\mathrm{X}}_2{\mathrm{Y}}_3$when 0.05 mole of${\mathrm{XY}}_2$ weighs 5 g while 3.011$\times$10²³ molecules of ${\mathrm{X}}_2{\mathrm{Y}}_3$ weighs 85 g. The atomic masses of x and y are respectively:

1.  20, 30

2.  30, 40

3.  40, 30

4.  80, 60

The impure 6 g of $\mathrm{NaCl}$ is dissolved in water and then treated with excess of silver nitrate solution. The weight of precipitate of silver chloride is found to be 14 g. The % purity of $\mathrm{NaCl}$ solution would be:

1.  95%

2.  85%

3.  75%

4.  65%

60 mL of a mixture of nitrous oxide and nitric oxide was exploded with excess of hydrogen. If 38 mL of ${\mathrm{N}}_2$ was formed, calculate the volume of each gas in the mixture. All measurements are made at constant P and T.

1.20 ml +30 ml

2. 44 ml + 16 ml

3. 10 ml+40 ml

4 .25 ml +25 ml

The haemoglobin from the red blood corpuscles of most mammals contains approximately 0.33% of iron by mass. The molar mass of haemoglobin as 67,200. The number of iron atoms in each molecule of haemoglobin is (atomic mass of iron=56):

1.  2

2.  3

3.  4

4.  5