Arrange the given compounds in decreasing order of boiling points.

I. CH₃CH₂CH₂CH₂Br

II. C(CH₃)₃Br

III. CH₃-CH₂-CH(CH₃)-Br

• I > III > II

• II > I > III

• I > II > III

• III > I > II

Two elements A and B form compounds of formula AB₂ and AB₄. When dissolved in 20.0 g of benzene 1.0 g of AB₂ lowers freezing point by 2.3°C whereas 1.0 g of AB₄ lowers freezing point by 1.3°C. The K_f for benzene is 5.1. The atomic masses of A and B are

• 25, 42

• 42, 25

• 52, 48

• 48, 52

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%

60 g of urea is dissolved in 1100 g solution. To keep $∆$Tf/Kf as 1 mol kg-1 water separated in the form of ice is :

• 40 g

• 60 g

• 100 g

• 200 g

Osmosis involved in :

• excretion of urine

• interchange of nutrients and waste products betweeen tissue cells and their surroundings

• in both cases

• None of the above

Vapour density of PCl₅ (g) dissociating into PCl₃ (g) and Cl₂ (g) is 100. Hence, van't Hoff factor for the case :

PCl₅ (g) $\rightleftharpoons$ PCl₃ (g) + Cl₂ (g) is :

• 1.85

• 3.70

• 1.085

• 1.0425

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.

Which salt is insoluble in water ?

• NH₄Cl

• KCl

• Na₂SO₄

• NaCl

279.

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.

What happens when chloroform is left open in air in the presence of sunlight?

• Explosion takes place

• Phosgene, a poisonous gas is formed.

• Polymerisation takes place.

• No reaction takes place.