Liquid ‘M’ and liquid ‘N’ form an ideal solution. The vapour pressures of pure liquids ‘M’ and ‘N’ are 450 and 700mm Hg, respectively, at the same temperature. Then correct statement is:

(x_M = Mole fraction of 'M' is solution; x_N = Mole fraction of 'N' in solution; y_M = Mole fraction of 'M' in vapour phase; y_N = Mole fraction of 'N' in vapour phase)

• $\frac{{\mathrm{x}}_{\mathrm{M}}}{{\mathrm{x}}_{\mathrm{N}}} < \frac{{\mathrm{y}}_{\mathrm{M}}}{{\mathrm{y}}_{\mathrm{N}}}$

• $\frac{{\mathrm{x}}_{\mathrm{M}}}{{\mathrm{x}}_{\mathrm{N}}} = \frac{{\mathrm{y}}_{\mathrm{M}}}{{\mathrm{y}}_{\mathrm{N}}}$

• $\frac{{\mathrm{x}}_{\mathrm{M}}}{{\mathrm{x}}_{\mathrm{N}}} > \frac{{\mathrm{y}}_{\mathrm{M}}}{{\mathrm{y}}_{\mathrm{N}}}$

• (x_M - y_M) < (x_N - y_N)

Equal moles of hydrogen and oxygen gases are placed in a container with a pin-hole through which both can escape. What fraction of the oxygen escapes in the time required for one-half of the hydrogen to escape?

• 1/4

• 3/8

• 1/2

• 1/2

Equal masses of H₂, O₂ and methane have been taken in a container of volume V at temperature 27⁰ C in identical conditions. The ratio of the volumes of gases H₂ : O₂: CH₄ would be 

• 8:16:1

• 16:8:1

• 16:1:2

• 16:1:2

When 22.4 L of H₂ (g) is mixed with 11.2 L of Cl₂ (g), each of at STP, the moles of HCl (g) formed is equal to

• 1 mole of HCl (g)

• 2 moles of HCl (g)

• 0.5 mole of (g) 

• 0.5 mole of (g) 

1.0 g of magnesium is burnt with 0.56 g of O₂ in a closed vessel. Which reactant is left in excess and how much?

• Mg, 0.16 g

• O₂, 0.16 g

• Mg, 0.44 g

• Mg, 0.44 g

516.

In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralised 10 mL of 1 M H₂SO₄.The percentage of nitrogen in the soil is

• 37.33

• 45.33

• 35.33

• 35.33

How many grams of the concentrated nitric solution should be used to prepare 250 mL o 2.0M HNO₃ ? The concentrated acid is 70% HNO₃.

• 45.0 g conc. HNO₃

• 90.0 g conc. HNO₃

• 70.0 g conc. HNO₃

• 70.0 g conc. HNO₃

6.02 x 10²⁰ molecules of urea are present in 100 mL of its solution. The concentration of solution is

• 0.02 M

• 0.01 M

• 0.001 M

• 0.001 M

Mole fraction of the solute in a 1.00 molal aqueous solution is 

• 0.0177

• 0.0344

• 1.7700

• 1.7700

Which one of the following statements is not true?

• Concentration of DO below 6 ppm is good for the growth of fish

• Clean water would have a BOD value of less than 5 ppm

• Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant

• Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant