31.

If 20 g of a solute was dissolve in 500 mL of water and osmotic pressure of the solution was found to be 600 mm of Hg at 15°C, then molecular weight of the solute is

• 1000

• 1200

• 1400

• 1800

Which of the following statement is false?

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

• The osmotic pressure ($\mathrm{\pi }$) of a solution is given by the equation T = MRT, where M is the molarity of the solution

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

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

In the reduction of KMnO₄ by warm acidified oxalic acid, the oxidation number of Mn changes from

• +4 to +2

• +6 to +4

• +7 to +2

• +7 to +4

Transition metals have the electronic configuration (n -1)d^1-10ns^1-2. The d-orbitals are degenerate. Colour of transition metal ions is due to absorption of some wavelength. This result is

• d-s transition

• s-d transition

• s-s transition

• d-d transition

Which one of the following statements regarding helium is incorrect ?

• It is used to fill gas balloons instead of hydrogen because it is lighter and non-inflammable

• It is used as a cryogenic agent for carrying out experiments at low temperatures

• It is used to produce and sustain powerful superconducting magnets

• It is used in gas cooled nuclear reactors

Wolframite ore is separated from tin stone ore by the process of

• roasting

• electromagnetic

• smelting

• calcination

The homogeneous catalysis is shown by

• Haber's process, N₂ + 3H₂ $\stackrel{\mathrm{Fe}}{\to }$ 2NH₃

• Ostwald process, 4NH₃ + 5O₂ $\stackrel{\mathrm{Pt}}{\to }$ 4NO + 6H₂O

• Contact process, 2SO₂ + O₂ $\stackrel{\mathrm{Pt}}{\to }$ 2SO₃

• 2C₂H₅OH $\stackrel{{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }$ C₂H₅-O-C₂H₅ + H₂O

Which of the reaction will yield  when reacted with base?

Which of the following is formed on reduction of oxalic acid with magnesium mercury amalgum and H₂SO₄?

• Glyoxalic acid

• Formic acid

• Glycolic acid

• CO₂ and H₂O

Which of the following nitro compounds are not soluble in NaOH?

• (CH₃)₃C-NO₂

• (CH₃)₂CH-NO₂

• CH₃CH₂-NO₂

• Ph-CH₂-NO₂