States of Matter

Mixing of N₂ and H₂ from an ideal gas mixture at room temperature in a container. For this process, which of the following statement is true?

• $∆\mathrm{H} = 0; ∆{\mathrm{S}}_{\mathrm{surrounding}} = 0; ∆{\mathrm{S}}_{\mathrm{system}} = 0 \mathrm{and} ∆\mathrm{G} = -\mathrm{ve}$

• $∆\mathrm{H} = 0; ∆{\mathrm{S}}_{\mathrm{surrounding}} = 0; ∆{\mathrm{S}}_{\mathrm{system}} > 0 \mathrm{and} ∆\mathrm{G} = -\mathrm{ve}$

• $∆\mathrm{H} > 0; ∆{\mathrm{S}}_{\mathrm{surrounding}} = 0; ∆{\mathrm{S}}_{\mathrm{system}} > 0 \mathrm{and} ∆\mathrm{G} = -\mathrm{ve}$

• $∆\mathrm{H} < 0; ∆{\mathrm{S}}_{\mathrm{surrounding}} > 0; ∆{\mathrm{S}}_{\mathrm{system}} < 0 \mathrm{and} ∆\mathrm{G} = -\mathrm{ve}$

Consider a fuel cell supplied with 1 mol of H₂ gas and 10 moles of O₂ gas. If fuel cell is operated at 9.63 mA current, how long will it deliver power? (Assume 1 F = 96500 C/mole of electrons).

• 1 × 10⁶ s

• 0.5 × 10⁶ s

• 2 × 10⁶ s

• 4 × 10⁶ s

Critical density of a gas having molecular weight 39 g mol^-1 is 0.1 × 10³ g cm^-3. Its critical volume in L mol^-1 is

• 0.390

• 3.90

• 0.039

• 39.0

18 g of glucose is dissolved in 178.2 g of water. The vapour pressure of the solution at 100° C is (vapour pressure of pure water at 100° C is 760 mm Hg)

• 767.6 mm Hg

• 760 mm Hg

• 752.4 mm Hg

• 725.4 mm Hg

If two moles of an ideal gas at 500 K occupies a volume of 41 L, the pressure of the gas is (R = 0.082 L atm K^-1 mol^-1)

• 2 atm

• 3 atm

• 4 atm

• 5 atm

At 273 K, the density of a certain gaseous oxide at 2 atm is same as that of dioxygen at 5 atm. The molecular mass of the oxide (in g mol^-1) is

• 80

• 64

• 32

• 160

Two vessels of volumes 16.4 L and 5 L contains two ideal gases of molecular existence at the respective temperature of 27°C and 227°C and exert 1.5 and 4.1 atm, respectively. The ratio of the number of molecules of the former to that of the later is

• 2

• 1

• $\frac{1}{2}$

• $\frac{1}{3}$

When 4 g of an ideal gas A is introduced into an evacuated flask kept at 25°C, the pressure is found to be one atmosphere. If 6 g of another ideal gas B is then added to the same flask, the pressure becomes 2 atm at the same temperature. The ratio of molecular weight (M_A : M_B) of the two gases would be

• 1 : 2

• 2 : 1

• 2 : 3

• 3 : 2

Identify an extensive property amongst the following.

• Viscosity

• Heat capacity

• Density

• Surface tension

The gas with the highest critical temperature is

• CO₂

• He

• N₂

• O₂