1➤
What are hypertonic solutions? Hypertonic solution:
=> If two solutions have unequal osmotic pressures, the more
concentrated solution with higher osmotic pressure is said to be
hypertonic solution.
2➤ What is a cryoscopic constant?
=> Ans: Cryoscopic constant: Cryoscopic constant is the depression in
freezing point produced by I molal solution of a nonvolatile
solute.
3➤
Write the effect of dissolution of a nonvolatile solute on the freezing
point of solvent.
=> The freezing point of solvent is lowered by the dissolution of
nonvolatile solute into it..
4➤ State Raoult's law.
=> Ans: Raoult's law states that the partial vapour pressure of any
volatile component of a solution is equal to the vapour pressure of the
pure component multiplied by its mole fraction in the solution.
5➤ State Henry's law.
=> Henry's law states that the solubility of a gas in a liquid is
directly proportional to the pressure of the gas over the
solution.
6➤
What type of solutions exhibit positive deviations from Raoult's
=> Ans: The solutions in which solute-solvent intermolecular
attractions weaker than those between solute-solute molecules and
solvent-solvent are molecules, exhibit positive deviations.
7➤
What is enthalpy change and volume change of mixing of two components
forming an ideal solution?
=> 1. No heat is evolved or absorbed when two components forming an
ideal solution are mixed. Thus, AH=0. There is no volume change when two
compo solution are mixed. Thus, Ami V-0. forming an ideal
8➤
The vapour pressures of pure liquids A and B are 0.600 bar and 0.933 bar
respectively, at a certain temperature. What is the mole fraction of
liquid B in the solution when the total vapour pressure of their mixture
is 0.8 bar?
=> alculation: From formula, P= (PP)x₂ + P 0.8 bar 933 bar -0.600 bar)
x₂ + 0.600 bar 0.333x₂ 0.8-0.60 0.2 0333 = 0.6
9➤
Explain relative lowering of vapour pressure.
=> Ans. Relative lowering of vapour pressure: If P, and P are the
respective vapour pressures of a pure liquid (solvent) and the solution
containing a nonvolatile solute then P
10➤
Anhydrous sodium sulphate dissolves in water with the evolution of heat.
What is the effect of temperature on its solubility?
=> Ans. Since the dissolution of anhydrous sodium sulphate in water is
an exothermic process due to evolution of heat, according to Le
Chatelier's principle, its solubility decreases with the increase in
temperature.
11➤
Why does the solubility of gases in liquids depend upon pressure?
=> Ans. (1) Since the gases are highly compressible, their solubility
in liquids is highly influenced by pressure changes. (2) As the external
pressure increases, the solubility increases at constant temperature.
the gases
12➤ What is point defect?
=> Ans. Point defect: The defect or imperfection produced in the
arrangement of a point like constituent particle, e.g. an atom or an ion
or a molecule in the crystalline structure is called point defect. The
point defects are classified as follows: (1) Vacancy defect. (2)
Interstitial defect. (3) Impurity defect.
13➤ What are hypotonic solutions?
=> Ans. Hypotonic solutions: When two solutions have different osmotic
pressures, then the solution having lower osmotic pressure is said to be
a hypotonic solution with respect to the other solution.
14➤ Give an example of an ideal solution.
=> Ans. A liquid mixture of benzene and toluene which have nearly
identical physical properties and intermolecular forces forms an ideal
solution.
15➤
Q. 15. What are the units of molal elevation constant?
=> Ans. Molal elevation constant, K, has units K kg mol-¹ (or °C kg
mol-¹) Therefore, molal elevation constant is the elevation in boiling
point produced by 1 molal solution of a atile solute.
16➤
What is cryoscopic constant (or molal depression constant)?
=> Ans. Molal depression constant: It is defined as the depression in
freezing point, produced by dissolving one mole of a solute in 1 kg (or
1000 g) of a solvent (i.e. 1 molal solution)..
