1) The relative lowering of vapour pressure is 0.4 for a solution containing 1 mole of NaCl in 3 mole H2O. The percentage ionization of NaCl is –
1) 60% 2) 50% 3) 100% 4) 40%
2) The number of conjugate acid-base pairs present in aqueous solution of NH3
1) 1 2) 2 3) 3 4) 4
3) The volume of water that must be added to a mixture of 250 ml of 6 M HCl and 750 ml of 2M HCl to obtain 2.5 M solution is – 250 ml 6M HCl vüΔ´ùç, 750 ml 2 M HCl
1) 75 ml 2) 150 ml 3) 100 ml 4) 200 ml
4) A Solution is prepared by dissoliving 3.5g of solute in 100 gm of solvent. At a certain temperature dry air is sent into the solution and solvent containers. The loss in weights of containers containing solution and solvent are 0.975 g and 0.025g respectively. The molecular weight of solvent is 75, then the
molarmass of solute?
1) 10.5 g 2) 105 g 3) 120 g 4) 1050g
5) Wrong statements of the following are
I) All Bronsted bases are Lewis bases
II) All Lewis acids are Bronsted acids
III) In acid-base reactions, the charge takes place in the direction of formation of stronger acid and stronger base.
IV) H2PO2 – acts as both Bronsted acid and Bronsted base
1) I, II 2) I, II, III 3) I, III, IV 4) II, III, IV
6) In electron alloy solute is
1) Mg 2) Zn 3) Al 4) Cu
7) 0.05 Moles of (NH4)2 SO4 is mixed with 500 ml of 0.2 M NH4 OH solution. Pkb of NH4OH is 4.76. The pH of the solution is-?
1) 9.24 2) 8.94 3) 9.54 4) 9.76
8) An acid buffer solution contains HX and NaX. A small amount of HCl is added to the buffer. The following reaction is responsible
to keep the pH constant.
1) Hx ←→ H++X- 2) Nax ←→ X- + Na+
3) Hx + OH- ←→ H2O+X- 4) X-+H+ ←→ HX
9) The following ion is not pricipitated from its solution on passing H2S in presence of HCl-
1) Co+2 2) Hg+2 3) Zn+2 4) Bi+3
10) The conjugate base of H2
1) H+ 2) H 3) H- 4) H2+
11) Which of the following is a buffer
1) 100 ml, 0.1 M CH3COOH + 100 ml, 0.1M NaOH
2) 125 ml, 0.2 M HCOOH + 250 ml, 0.1 M KOH
3) 125 ml, 0.1 M NH4OH + 50 ml of 0.1 M HCl
4) 25 ml, 0.1 M NH4OH + 50 ml, 0.1 M HCl
12) Volume of 0.02 M KMNO4 solution required for the oxidation of 50 ml of 0.05 M Oxalic acid solution in acidic medium is —-
1) 25 ml 2) 50 ml 3) 75 ml 4) 100 ml
13) Which concentration can be calculated if the mole fraction and density of an aqueous solution of HCl are known
I) Molality II) Molarity III) Percent by mass
1) I only 2) I, II only 3) II, III only 4) I, II, III
14) A: HSO4- is a Bronsted acid as well as Bronsted base
R: H2SO4 is a dibasic acid
1) Both A & R are true and R explains ‘A’
2) Both A & R are true and R doesn’t explain ‘A’
3) A is true, R is false
4) A is false but R is true
15) A: Vapour pressure of liquid increases with increase of surface area of the liquid at a given temperature
R: Rate of evaporation of liquid increases with increase of surface area of the liquid at a given temperature.
1) Both A & R are true, and R is correct explanation of A
2) Both A & R are true, but R is not correct explanation of A
3) A is true but R is false
4) A is false but R is true.
16) The Ka of CH3COOH is 2 × 10-5. The pH of 0.2 M CH3COOH solution is
1) 0.699 2) 1.699 3) 2.301 4) 2.699
17) The pH of a solution is 5.5. Then the number of moles of H+ ions present in 1000 ml of that solution (anti log of 0.5 = 3.125)
1) 3.125 × 10-3 2) 3.125 × 10-4
3) 3.125 × 10-5 4) 3.125 × 10-6
18) Rast’s method is generally used for the solutions of
1) Solid in liquid 2) Liquid in Solid
3) Solid in Solid 4) Solid in gas
19) Boiling point of an aqueous solution is 101.04oC. The freezing point of the same solutin is (Kb and Kf of water are 0.52 & 1.86 K.Kg. Mol-1 respectively)
1) -3.72oc 2) -1.86oc 3) -0.372oc 4) -0.186oc
KEY : 1)1 2)2 3)4 4)2 5)4 6)1 7)2 8)4 9)4 10)3 11)3 12)2 13)4 14)2 15)4 16)4 17)3 18)3 19)1