21.

The enthalpies of combustion of carbon and carbon monoxide are -393.5 and -283 kJ mol^-1 respectively. The enthalpy of formation of carbon monoxide per mole is

• 110.5 kJ

• -110.5 kJ

• -676.5 kJ

• -676.5 kJ

The ammonia evolved from the treatment of 0.30 g of an organic compound for the estimation of nitrogen was passed in 100 mL of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5 M sodium hydroxide solution hydroxide solutio for complete neutralization. The organic compound is

• acetamide

• thiourea

• urea

• urea

The smog is essentially caused by the presence of

• O₂ and O₃

• O₃ and N₂

• Oxides of sulphur and nitrogen

• Oxides of sulphur and nitrogen

Which one of the following aqueous solutions will exhibit highest boiling point?

• 0.01 M Na₂SO₄

• 0.015 M glucose

• 0.015 M urea

• 0.015 M urea

Which among the following factors is the most important in making fluorine the strongest oxidizing halogen?

• Electron affinity

• Bond dissociation energy

• Hydration enthalpy

• Hydration enthalpy

6.02×10²⁰ molecules of urea are present in 100 ml of its solution. The concentration of urea solution is

• 0.001 M

• 0.1 M

• 0.02 M

• 0.02 M

To neutralize completely 20 mL of 0.1 M aqueous solution of phosphorous acid (H₃PO₃), the volume of 0.1 M aqueous KOH solution required is

• 10 mL

• 60 mL

• 40 mL

• 40 mL

For which of the following parameters the structural isomers C₂H₅OH and CH₃OCH₃ would be expected to have the same values?

• Heat of vaporization

• Gaseous densities at the same temperature and pressure

• Boiling points

• Boiling points

Which of the following liquid pairs shows a positive deviation from Raoult’s law?

• Water – hydrochloric acid

• Acetone – chloroform

• Water – nitric acid

• Water – nitric acid

Which one of the following statements is false?

• Raoult’s law states that the vapour pressure of a components over a solution is proportional to its mole fraction

• Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression

• The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is BaCl₂ > KCl > CH₃COOH > sucrose

• The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is BaCl₂ > KCl > CH₃COOH > sucrose