CBSE
Multiple Choice QuestionsA 0.0020 m aqueous solution of an ionic compound Co(NH3)5(NO2)Cl freezes at -0.00732o C . Number of moles of ions which 1 mol of ionic compound produces on being dissolved in water will be (kf = - 1.86o C/m)
2
3
4
4
The van't Hoff factor, i for a compound which undergoes dissociation in one solvent and association in other solvent is respectively.
Less than one and less than one
Greater than one and less than one
Greater than one and greater than one
Greater than one and greater than one
What is the [OH-] in the final solution prepared by mixing 20.0 mL of 0.50 M HCl with 30.0mL of 0.10 Ba(OH)2?
0.10 M
0.40 M
0.0050 M
0.0050 M
The freezing point depression constant for water is -1 . 86o C m-1. If 5.00 g Na2SO4 is dissolved in 45.0 g H2O, the freezing points is changed by -3.82oC. Calculate the van't Hoff factor for Na2SO4.
2.63
3.11
0.381
0.381
An aqueous solution is 1.00 molal in KI. Which change will cause the vapour pressure of the solution to increase?
Addition of NaCl
Addition of Na2SO4
Addition of 1.00 molal KI
Addition of 1.00 molal KI
200 mL of an aqueous solution of a protein contains its 1.26 g . The osmotic pressure of this solution at 300 K is found to be 2.57 x 10-3 bar. The molar mass of protein will be (R = 0.083 L bar mol-1 K-1)
51022 g mol-1
122044 g mol-1
31011 g mol-1
31011 g mol-1
A solution of sucrose (molar mass = 342 g mol-1) has been prepared by dissolving 68.5 g of sucrose in 1000 g of water. The freezing point of the solution obtained will be (kf for water = 1.86 K kg mol-1)
-0.372o C
-0.520o C
+0.372o C
+0.372o C
A 0.1 molal aqueous solution of a weak acid is 30% ionised. if Kf for water is 1.86oC/m, the freezing point of the solution will be
-18oC
-0.54oC
-0.36oC
-0.36oC
Concentrated aqueous sulphuric acid is 98% H2SO4by mass and has a density of 1.80 g mL-1.Volume of acid required to make one litre of 0.1 M H2SO4 solution is:
11.10 mL
16.65 mL
22.20 mL
22.20 mL
25.3 g of sodium carbonate, Na2CO3 is dissolved in enough water to make 250 mL of solution. If sodium carbonate dissociates completely molar concentration of sodium ion, Na+ and carbonate ion, CO32- are respectively (Molar mass of Na2CO3 = 106 g mol-1)
0.955 M and 1.910 M
1.910 M and 0.955 M
1.90 M and 1.910 M
1.90 M and 1.910 M
