What is meant by positive deviations from Raoult’s law ? Give an example. What is the sign of H for positive deviation ?
In case of positive deviation from Raoult’s law, the intermolecular attractive forces between the solutesolvent molecules are weaker than those between the solute-solute and solvent-solvent molecules.
Example: Mixture of ethanol and acetone.
Sign for H is positive
Example: Mixture of ethanol and acetone.
Sign for H is positive
What type of intermolecular attractive interaction exists in the pair of methanol and acetone ?
State Henry’s law. What is the effect of temperature on the solubility of a gas in a liquid ?
State Raoult’s law for the solution containing volatile components. What is the similarity between Raoult’s law and Henry’s law ?
Why a mixture of Carbon disulphide and acetone shows positive deviation from Raoult’s law? What type of azeotrope is formed by this mixture?
Define the following terms :
(i) Molar conductivity (),
(ii) Secondary batteries.
Explain the following observations:
(i) Copper atom has completely filled d orbitals (3d¹⁰) in its ground state, yet it is regarded as a transition element.
(ii) Cr²⁺ is a stronger reducing agent than Fe²⁺ in aqueous solution.
In a galvanic cell, the following cell reactions occurs:
E°cell = +1.56 V
(i) Is the direction of flow of electrons from zinc to silver or silver to zinc?
(ii) How will concentration of Zn²⁺ ions and Ag⁺ ions be affected when the cell functions?
When chromite ore FeCr₂O₄ is fused with NaOH in presence of air, a yellow coloured compound
(A) is obtained which on acidification with dilute sulphuric acid gives a compound (B). Compound (B) on reaction with KCl forms a orange coloured crystalline compound (C).
(i) Write the formulae of the compounds (A), (B) and (C).
(ii) Write one use of compound (C).