Assignment No – 3
d & f Block Elements
Que 1. Which is a stronger reducing agent
Cr2+ or Fe2+ and why?
Que 2. Explain briefly how +2 state
becomes more and more stable in the first half of the first-row transition
elements with increasing atomic number?
Que 3. The Chemistry of the actinoid
elements is not so smooth as that of the lanthanoids. Justify this statement by
giving some examples from the oxidation state of these elements.
Que 4. Write complete chemical equations
for:
(i) Oxidation of Fe2+ by Cr2O72–
in acid medium.
(ii) Oxidation of S2O32–
by MnO4– in neutral aqueous solution.
Que 5. Assign reasons for each of the
following:
(i) Transition metals generally form
coloured compounds.
(ii) Manganese exhibits the highest
oxidation state of +7 among the 3d series of transition elements
Que 6. (i) A black mineral (A) on
treatment with dilute sodium cyanide solution in presence of air gives a clear
solution of (B) and (C).
(ii) The solution (B) on reaction with
zinc gives precipitate of a metal (D).
(iii) (D) is dissolved in dilute HNO3
and the resulting solution gives a white precipitate (E) with dilute HCl.
(iv) (E) on fusion with sodium carbonate
gives (D).
(v) (E) dissolves in ammonia solution
giving a colourless solution of
(F). Identify (A) to (F) and give chemical
equations for reactions at steps (i) to (v).
Que
7. Explain which one of the following is a good oxidizing agent:
Sc3+, Ce4+or
Eu2+ (atomic of Sc=21, Ce=58, Eu=63)To Get The Answers Click The Link Below:
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