REDOX TITRATIONS:

LAW OF EQUIVALENT WEIGHT:

No of equivalent of A reacted = No of equivalent of B reacted = No of equivalent of C formed = No of equivalent of D formed

RELATION BETWEEN NORMALITY (N) AND MOLARITY (M):

SOME COMMON OXIDISING AGENT:

SOME COMMON REDUCING AGENT:

ILLUSTRATIVE EXAMPLE (1): Calculate the moles of KMnO₄ required to reacting with 180 gm of Oxalic acid (H₂C₂O₄). Also calculate the volume of CO2 at STP produce in the reaction? (K=39, Mn=55, Of=16)

SOLUTION:

ILLUSTRATIVE EXAMPLE (2): Calculate the weight of K₂Cr₂O₇ which reacts with KI to liberate 254 gm of I₂ ?.(Cr=51.9961, I=127)

SOLUTION:

ILLUSTRATIVE EXAMPLE (3): Calculate volume of 0.05 M KMnO₄ required to react with 50 ml of 0.1M H₂S in acidic medium , given H₂S oxidized to SO₂?.

SOLUTION:

ILLUSTRATIVE EXAMPLE (4): Calculate the mass of Fe₃O₄ required to react completely with 25 ml of 0.3 M K₂Cr₂O₇?.

SOLUTION:

ILLUSTRATIVE EXAMPLE (5): Calculate the concentration of H₂O₂ if 20 ml H₂O₂ Solution react with 10 ml of 2M KMnO₄ in acidic medium ?

SOLUTION:

ILLUSTRATIVE EXAMPLE (6): Calculate the moles of KCl which  required to produce 10 ml of Cl₂ when reacted with KClO₃ ?

SOLUTION:

ILLUSTRATIVE EXAMPLE (7): Calculate the moles of KMnO₄ required for Oxidation of 1.25 moles Cu₂S.

SOLUTION:

ILLUSTRATIVE EXAMPLE (8): Calculate the Molarity of H₂O₂ if 11.2 ml H₂O₂ require 30 ml of 0.5 M K₂Cr₂O₇ for its Oxidation . also calculate the volume of strength of H₂O₂.

SOLUTION:

ILLUSTRATIVE EXAMPLE (9): 696 gm of Fe₂O₃ and FeO reacts completely with 158 gm of KMnO₄ in acidic medium . Calculate the composition of mixture.

SOLUTION:

ILLUSTRATIVE EXAMPLE (10): 829 gm of K₂Cr2O₇ and H₂C₂O₄ reacts  completely with 7/3 moles of K₂Cr₂O₇ .
(1) Calculate the moles of each in mixture.
(2) Calculate the moles of NaOH required to react with above mixture.

SOLUTION:

ILLUSTRATIVE EXAMPLE (11): 50ml of KMnO₄ is mixed with excess of KI the I₂ liberated require 30 ml of 0.1M Na₂S₂O₃ solution calculate the Molarity of KMnO₄ solution.

SOLUTION:

ILLUSTRATIVE EXAMPLE (12): 50 Cm³ of 0.04 M K₂Cr₂O₇ in acidic medium oxidized a sample  of H₂S gas to Sulphur . The volume of 0.03 M KMnO₄ required to Oxidize the same amount of H₂S gas to Sulphur, in acidic medium is.

SOLUTION:

ILLUSTRATIVE EXAMPLE (13): What volume of 0.4 M Na₂S₂O₃ would be required to react with the I₂ liberated by adding excess of KI to 50 ml of 0.2 M CuSO₄? (Ans= 25 ml).

SOLUTION: Try yourself .......
Dowmload as pdf click here

BORON:

Boron is metalloids of 13^th group and it does not occur in Free State. The major ores of boron are a small number of borate (boron oxide) minerals, including

PREPARATION OF BORON:

(1) From Borax: Boron may be obtained by treating borax with hot concentrated HCl, or H₂SO_4,  igniting the boric acid H₃BO₃ to give the oxide B₂O₃ and finally reduced with Na, K, Al, Mg.

Step-(1) conversion of borax into boron oxide:

Step-(2) conversion of Boron oxide into boron:

(2) From Colemanite:

Physical properties:

(1) It is a non-metal. Boron occurs in two different allotropic forms Amorphous and   Crystalline

(2) Amorphous boron has not been obtained in the pure state.

(3) Crystalline boron is a black powder, extremely hard with a metallic appearance but with very low electrical conductivity.

Chemical properties:

(1) Reaction with non oxy acids:

(2) Reaction with Oxy acids:

(3) Reaction with Oxy water:

(4) Reaction with Base:

(5) Reaction with Metals:

(6) Reaction with Non-metals

 (7) Reaction with Ammonia:

Structure of Borazine: