D and F Block Elements MCQ Questions & Answers in Inorganic Chemistry | Chemistry
Learn D and F Block Elements MCQ questions & answers in Inorganic Chemistry are available for students perparing for IIT-JEE, NEET, Engineering and Medical Enternace exam.
301.
The most common lanthanoid is
A
lanthanum
B
cerium
C
samarium
D
plutonium
Answer :
cerium
No explanation is given for this question. Let's discuss the answer together.
302.
Knowing that the chemistry of lanthanoids $$(Ln)$$ is dominated by its + 3 oxidation state, which of the following statements is incorrect ?
A
The ionic size of $$Ln\left( {{\text{III}}} \right)$$ decrease in general with increasing atomic number.
B
$$Ln\left( {{\text{III}}} \right)$$ compounds are generally colourless.
C
$$Ln\left( {{\text{III}}} \right)$$ hydroxide are mainly basic in character.
D
Because of the large size of the $$Ln\left( {{\text{III}}} \right)\,ions$$ the bonding in its compounds is predominantly ionic in character.
Answer :
$$Ln\left( {{\text{III}}} \right)$$ compounds are generally colourless.
Most of the $$L{n^{3 + }}$$ compounds except $$L{a^{3 + }}$$ and $$L{u^{3 + }}$$ are coloured due to the presence of $$f$$ - electrons.
303.
Potassium dichromate is prepared from
A
chromate obtained by the fusion of chromite ore with sodium carbonate in free access of air
B
pyrolusite which is fused with potassium hydroxide in the presence of air
C
iron pyrites by the fusion with potassium carbonate in presence of moisture
D
none of these
Answer :
chromate obtained by the fusion of chromite ore with sodium carbonate in free access of air
304.
$$C{u^ + }$$ ion is not stable in aqueous solution because
A
second ionisation enthalpy of copper is less than the first ionisation enthalpy
B
large value of second ionisation enthalpy of copper is compensated by much more negative hydration energy of $$Cu_{\left( {aq} \right)}^{2 + }$$
C
hydration energy of $$Cu_{\left( {aq} \right)}^{ + }$$ is much more negative than that of $$Cu_{\left( {aq} \right)}^{2 + }$$
D
many copper $$\left( I \right)$$ compounds are unstable in aqueous solution and undergo disproportionation reaction
Answer :
large value of second ionisation enthalpy of copper is compensated by much more negative hydration energy of $$Cu_{\left( {aq} \right)}^{2 + }$$
No explanation is given for this question. Let's discuss the answer together.
305.
Match the column I with column II and mark the appropriate choice.
Column I
Column II
a.
$$Ni$$ in the presence of hydrogen
1.
Ziegler Natta catalyst
b.
$$C{u_2}C{l_2}$$
2.
Contact process
c.
$${V_2}{O_5}$$
3.
Vegetable oil to ghee
d.
Finely divided iron
4.
Sandmeyer reaction
e.
$$TiC{l_4} + Al{\left( {C{H_3}} \right)_3}$$
5.
Haber's process
A
a - 4, b - 2, c - 3, d - 1, e - 5
B
a - 2, b - 5, c - 1, d - 3, e - 4
C
a - 5, b - 3, c - 4, d - 2, e - 1
D
a - 3, b - 4, c - 2, d - 5, e - 1
Answer :
a - 3, b - 4, c - 2, d - 5, e - 1
No explanation is given for this question. Let's discuss the answer together.
306.
Metallic radii of some transition elements are given below. Which of these elements will have highest density?
Element
$$Fe$$
$$Co$$
$$Ni$$
$$Cu$$
Metallic radii/pm
126
125
125
128
A
$$Fe$$
B
$$Ni$$
C
$$Co$$
D
$$Cu$$
Answer :
$$Cu$$
All the four metals have nearly the same metallic radii and hence nearly the same atomic volume. On account of higher atomic mass of copper it has high density amongst given metals.
307.
Which of the following dissolve in hot conc.$$NaOH$$ solution
Among these alloys, only steel contains carbon which is a non-metal.
309.
$$CuS{O_4}$$ when reacts with $$KCN$$ forms $$CuCN$$ which is insoluble in water. It is soluble in excess of $$KCN$$ due to the formation of the complex
A
$${K_2}\left[ {Cu{{\left( {CN} \right)}_4}} \right]$$
B
$${K_3}\left[ {Cu{{\left( {CN} \right)}_4}} \right]$$
C
$$Cu{\left( {CN} \right)_2}$$
D
$$Cu\left[ {KCu{{\left( {CN} \right)}_4}} \right]$$
$$CuS{O_4}$$ reacts with $$KCN$$ to give a white precipitate of cuprous cyanide and cyanogen gas. The cuprous cyanide dissolves in excess of $$KCN$$ forming $${K_3}\left[ {Cu{{\left( {CN} \right)}_4}} \right].$$
$$\eqalign{
& CuS{O_4} + 2KCN \to {K_2}S{O_4} + \mathop {Cu{{\left( {CN} \right)}_2}}\limits_{{\text{Unstable}}} \cr
& 2Cu{\left( {CN} \right)_2} \to \mathop {2CuCN}\limits_{{\text{Insoluble}}} + \mathop {CN - CN}\limits_{{\text{cyanogen}}} \cr
& CuCN + 3KCN \to \mathop {{K_3}\left[ {Cu{{\left( {CN} \right)}_4}} \right]}\limits_{{\text{Soluble}}} \cr} $$
310.
In the following reactions, $$ZnO$$ is respectively acting as a/an:
$$\eqalign{
& \left( A \right)\,\,ZnO + N{a_2}O \to N{a_2}Zn{O_2} \cr
& \left( B \right)\,\,ZnO + C{O_2} \to ZnC{O_3} \cr} $$
A
base and acid
B
base and base
C
acid and acid
D
acid and base
Answer :
acid and base
Although $$ZnO$$ is an amphoteric oxide but in given reaction.
$$\eqalign{
& \left( A \right)\,\mathop {ZnO}\limits_{acid} + \mathop {N{a_2}O}\limits_{base} \to \mathop {N{a_2}Zn{O_2}}\limits_{salt} \cr
& \left( B \right)\,\mathop {ZnO}\limits_{base} + \mathop {C{O_2}}\limits_{acid} \to \mathop {ZnC{O_3}}\limits_{salt} \cr} $$