CBSE
Multiple Choice QuestionsThe mass of carbon anode consumed (giving only carbondioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is (Atomic mass Al= 27)
180 kg
270 kg
540 kg
90 kg
The significant figures in 1.0024, 1.240 and 0.0020 are respectively
5, 4, 2
3, 3, 1
5, 3, 4
5, 3, 2
A solution has a 1 : 4 mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at 20C are 440 mm of Hg for pentane and 120 mm of Hg for hexane. The mole fraction of pentane in the vapour phase would be
0.549
0.200
0. 786
0.478
A 0.5 g/L solution of glucose is found to be isotonic with a 2.5 g/L solution of an organic compound. What will be the molecular weight of that organic compound ?
300
600
900
200
The pH of a 0.001 M solution of HCl is
0
3
5
10
The number of moles of KMnO4 reduced by one mole of KI in alkaline medium is
one-fifth
five
one
two
A cylinder of compressed gas contains nitrogen and oxygen in the ratio of 3:1 by mole. The total mass of the gas mixture if the cylinder is known to contain 2.5 x 104 g of oxygen will be:
8 x 103 g
9 x 104 g
9 x 103 g
8 x 102 g
The vapour pressure of pure water is 25.0 mm Hg and that of an aqueous dilute solution of urea in 20mm Hg at 25°C. The molarity of the solution is:
12.6
14.9
13.8
9.6
0.1 mol HCl is equal to
3.65 g
36.5 g
18 g
1.8 g
If for a sucrose solution, elevation in boiling point is 0.1°C, then what will be the boiling point of NaCl solution for same molal concentration ?
0.1C
0.2C
0.08C
0.01C
