Na2SO4. 10H2O crystals are formed by cooling 100 Kg of 30% by weight aqueous solution of Na2SO4. The final concentration of the solute in the solution is 10%. The weight of crystals is________________?

Related Mcqs:

1. 80 kg of Na2SO4 (molecular weight = 142) is present in 330 kg of an aqueous solution. The solution is cooled such that. 80 kg of Na2SO4 .10H2O crystals separate out. The weight fraction of Na2SO4 in the remaining solution is_________________?

   A. 0.00
   B. 0.18
   C. 0.24
   D. 1.00

2. In general, the specific heats of aqueous solutions _____________ with increase in the concentration of the solute?

   A. Increase
   B. Decrease
   C. Remain unchanged
   D. None of these

3. With increase in the solute concentration, the specific heat of aqueous solutions _____________________?

   A. Increases
   B. Decreases
   C. Remains unchanged
   D. Either A. or B.; depends on the type of solution

4. A very dilute solution is prepared by dissolving ‘x1’ mole of solute in ‘x2’ mole of a solvent. The mole fraction of solute is approximately equal to_________________?

   A. x1/x2
   B. x2/x1
   C. 1 – (x1/x2)
   D. 1/x2

5. The vapor pressure of the solvent decreased by 10 mm Hg, when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraction of the solvent, if the decrease in vapor pressure of the solvent is required to be 20 mm Hg ?

   A. 0.2
   B. 0.1
   C. 0.4
   D. 0.6

6. In case of a ternary system involving two liquid components and a solute, the ratio of the concentration of the solute in the two phases at equilibrium is called the distribution co-efficient. The distribution co-efficient depends upon the______________?

   A. Solute concentration
   B. Temperature
   C. Both A. & B.
   D. Neither A. nor B.

7. An aqueous solution of 2.45% by weight H2SO4 has a specific gravity of 1.011. The composition expressed in normality is______________?

   A. 0.2500
   B. 0.2528
   C. 0.5000
   D. 0.5055

8. A solution is made by dissolving 1 kilo mole of solute in 2000 kg of solvent. The molality of the solution is_________________?

   A. 2
   B. 1
   C. 0.5
   D. 0.05

9. The weight fraction of methanol in an aqueous solution is 0.64. The mole fraction of methanol XM satisfies________________?

   A. XM < 0.5
   B. XM = 0.5
   C. 0.5 < XM < 0.64
   D. XM ≥ 0.64

10. Acidity or alkanity of a solution is expressed by its pH value, which is defined as (where, [H+] = hydrogen ion concentration in the solution) ?

    A. log (1/H+)
    B. – log (1/H+)
    C. 1/log H+
    D. None of these