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 Kf 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 Kf for benzene = 5.12K kg mol-1) Mobserved 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
C.
in both cases
Osmosis is involved in both the processes , i.e. , in excretion of urine and in interchange of nutrients and waste products between tissue cells and their surroundings.
Vapour density of PCl5 (g) dissociating into PCl3 (g) and Cl2 (g) is 100. Hence, van't Hoff factor for the case :
PCl5 (g) 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.
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.