The freezing point of a solution containing 0.2 g of acetic acid in 20.0 g benzene is lowered by 0.45°C. The degree of association of acetic acid in benzene is (Assume acetic acid dimerises in benzene and K_f for benzene = 5.12K kg mol^-1) M_observed of acetic acid =  113.78

• 94.5%

• 54.9%

• 78.2%

• 100%

Which of the following can be oxidised by SO₂?

• K₂Cr₂O₇

• Mg

• H₂O

• All of these

A conductivity cell has a cell constant of 0.5 cm^-1. This cell when filled with 0.01 M NaCl solution has a resistance of 384 ohms at 25°C. Calculate the equivalent conductance of the given solution.

• 130.2 ${\Omega }^{-1}$ cm² (g eq)^-1

• 137.4 ${\Omega }^{-1}$ cm² (g eq)^-1

• 154.6 ${\Omega }^{-1}$ cm² (g eq)^-1

• 169.2 ${\Omega }^{-1}$ cm² (g eq)^-1

Assertion : Co[Hg(SCN)₆] and Hg [Co(SCN)₆] are isomers.

Reason : SCN^- is a stronger ligand as compared to NCS^-.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false.

• If both assertion and reason are false

Assertion : Acetone and aniline shows negative deviations.

Reason : H-bonding between acetone and aniline is stronger than that between acetoneacetone and aniline-aniline.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion : Charcoal is used in separation of noble gases.

Reason : Charcoal has porous structure

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : A solution of sucrose in water is dextrorotatory. But on hydrolysis in the presence of a little hydrochloric acid, it becomes laevorotatory.

Reason : Sucrose on hydrolysis gives unequal amounts of glucose and fructose. As a result of this, change in sign ofrotation is observed.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : In electrolysis, the quantity of electricity needed for depositing 1 mole of silver is different from that required for 1 mole of copper.

Reason : The molecular weights of silver and copper are different.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false.

• If both assertion and reason are false

49.

The acidic strength of the given compounds follows the order

I. CH₃-CH=CH-COOH

II. CH₃-$\underset{..}{\overset{..}{\mathrm{O}}}$-CH=CH-COOH

III. CH₃=CH₂-COOH

• II > III > I

• III > II > I

• II > I > III

• I > II > III

Benzaldehyde can be prepared from