Good Chemistry Questions

A student was assigned a certain task by his teacher in chemistry lab. During the experiment, student dropped the flask containing 250 ml, 3 molar NaOH solution. Due to this 50 ml of solution out of 250 ml, had fallen on the floor. Thinking that teacher may punish him for this mistake, he replenished the left over solution with 50 ml of water. The new molarity of NaOH solution will be.
(A) 2M (B) 3M (C) 2.5 M (D) 2.4 M
2.* Which of the following molarity values of ions in a aqueous solution of 5.85 % w/v NaCl, 5.55% w/v CaCl2 and
6% w/v NaOH are correct [Na = 23, Cl = 35.5 , Ca = 40, O = 16 ]
(A) [Cl–1] = 2M (B) [Na+] = 1M (C) [Ca2+] = 0.5 M (D) [OH–] = 1.5 M
3. For an ideal binary solution with PA
0 / PB
0 which relation between XA (mole fraction of A in liquid phase) and YA
(mole fraction of A in vapour phase) is correct , XB and YB are mole fraction of B in liquid and vapour phase respectively : (Given : PA
0 > PB
0 )
(A) XA = YA (B) XA > YA
(C)
B
A
X
X
<
B
A
Y
Y
(D) XA, YA, XB and YB cannot be correlated (XA, YA, XB)
4. In which case van’t Hoff factor is maximum ?
(A) KCl, 50% ionised (B) K2SO4, 40% ionised (C) SnCl4, 20% ionised (D) FeCl3, 30% ionised
5. Solution having osmotic pressure nearer to that of an equimolar solution of K4[Fe(CN)6] is:
(A) Na2SO4 (B) BaCl2 (C) Al2(SO)3 (D)C12 H22O11
6.(a) Two aqueous solutions, one of the NaCl in water (A) and the other of C8H15O2Na in water (B) are isotonic. If wA and wB are weight fractions of NaCl and C8H15O2Na in solution A and B respectively, then (assuming that both the salts dissociate completely) :
(A) wA > wB (B) wA = wB (C) wA < wB (D) none of these
6(b). An electrolyte A gives 3 ions and B is a non-electrolyte. If 0.1 M solution of B produces an osmotic pressure P, then 0.05 M solution of A will produce an osmotic pressure, assuming that the electrolyte is completely ionised
(A) 1.5 P (B) P (C) 0.5 P (D) 0.75 P
7. The osmotic pressure of equimolar solutions of BaCl2,