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.
81.
Among the following metal carbonyls, the $$C - O$$ bond order is lowest in
A
$${\left[ {Mn{{\left( {CO} \right)}_6}} \right]^ + }$$
B
$$\left[ {Fe{{\left( {CO} \right)}_5}} \right]$$
C
$$\left[ {Cr{{\left( {CO} \right)}_6}} \right]$$
D
$${\left[ {V{{\left( {CO} \right)}_6}} \right]^ - }$$
An anionic carbonyl complex can delocalise more electron density to antibonding $$pi$$ - orbital of $$CO$$ and hence, lowers the bond order.
82.
The reason for greater range of oxidation states in actinoids is attributed to
A
the radioactive nature of actinoids
B
actinoid contraction
C
$$5f, 6d$$ and $$7s$$ levels having comparable energies
D
$$4f$$ and $$5d$$ levels being close in energies
Answer :
$$5f, 6d$$ and $$7s$$ levels having comparable energies
The reason for greater range of oxidation states in actinoid is attributed to the $$5f, 6d$$ and $$7s$$ levels having comparable energies.
The $$5f$$-orbitals extend into space beyond the $$7s$$ and $$6 p$$ -orbitals and participate in bonding. This is in direct contrast to the lanthanides where the $$4f$$-orbitals are buried deep inside the atom, totally shielded by outer orbitals and thus unable to take part in bonding.
83.
A compound of iron exists as a dimer in vapour state. It is hygroscopic in nature and dissolves in water giving brown acidic solution. The compound is
A
$$F{e_3}{O_4}$$
B
$$FeS{O_4}$$
C
$$FeC{l_3}$$
D
$$Fe{O_2}$$
Answer :
$$FeC{l_3}$$
The solution is acidic due to formation of $$HCl$$ and brown due to $$Fe{\left( {OH} \right)_3}.$$
$$FeC{l_3} + 3{H_2}O \to Fe{\left( {OH} \right)_3} + 3HCl$$
84.
Mercury is a liquid metal because
A
it has a completely filled $$d$$ - orbital that prevents $$d{\text{ - }}d$$ overlapping of orbitals
B
it has a completely filled $$d$$ - orbital that causes $$d{\text{ - }}d$$ overlapping
C
it has completely filled $$s$$ - orbital
D
it has small atomic size
Answer :
it has a completely filled $$d$$ - orbital that prevents $$d{\text{ - }}d$$ overlapping of orbitals
The more extensive the metallic bonding of an element, the more will be its enthalpy of atomization. Due to the absence of unpaired electrons in zinc, metallic bonding is weakest and as a result, it has least enthalpy of atomization.
85.
Which of the following is an organometallic compound?
A
Lithium methoxide
B
Lithium acetate
C
Lithium dimethylamide
D
Methyl lithium.
Answer :
Methyl lithium.
Organometallic compounds are those compounds in which metal atom is directly bonded with $$C - \,atom.\,\,{H_3}C - Li.$$
86.
Match the column I with column II and mark the appropriate choice.
Column I
Column II
a.
Mischmetal
1.
Alloy of $$Cu$$ and $$Sn$$
b.
Ziegler catalyst
2.
Alloy of lanthanoid metals
c.
Brass
3.
$$TiC{l_4} + Al{\left( {C{H_3}} \right)_3}$$
d.
Bronze
4.
Alloy of $$Cu$$ and $$Zn$$
A
a - 1, b - 3, c - 2, d - 4
B
a - 2, b - 3, c - 4, d - 1
C
a - 4, b - 1, c - 3, d - 2
D
a - 3, b - 2, c - 1, d - 4
Answer :
a - 2, b - 3, c - 4, d - 1
No explanation is given for this question. Let's discuss the answer together.
87.
The electronic configuration of $$Cu\left( {{\text{II}}} \right)$$ is $$3{d^9}$$ whereas that of $$Cu\left( {\text{I}} \right)$$ is $$3{d^{10}}.$$ Which of the following is correct?
A
$$Cu\left( {{\text{II}}} \right)$$ is more stable.
B
$$Cu\left( {{\text{II}}} \right)$$ is less stable.
C
$$Cu\left( {\text{I}} \right)$$ and $$Cu\left( {{\text{II}}} \right)$$ are equally stable.
D
Stability of $$Cu\left( {\text{I}} \right)$$ and $$Cu\left( {{\text{II}}} \right)$$ depends on nature of copper salts.
Answer :
$$Cu\left( {{\text{II}}} \right)$$ is more stable.
Standard electrode potential of $$C{u^ + }$$ is high $$\left( {0.52\,V} \right)$$ as compared to $$C{u^{2 + }}\left( {0.34\,V} \right),$$ hence $$C{u^ + }$$ is reduced more easily and is less stable than $$C{u^{2 + }}.$$
88.
Which of the following ions does not exist?
A
$${\left[ {Cu{I_4}} \right]^{2 - }}$$
B
$$VO_4^{3 - }$$
C
$$WO_4^{2 - }$$
D
$$CrO_4^{2 - }$$
Answer :
$${\left[ {Cu{I_4}} \right]^{2 - }}$$
$${\left[ {Cu{I_4}} \right]^{2 - }}$$ does not exist because $${I^ - }$$ being a stronger reducing agent reduces $$C{u^{2 + }}$$ to $$C{u^ + }.$$
$$2Cu{I_2} \to 2CuI + {I_2}$$
89.
In which of the following lanthanoids oxidation state $$+2$$ is most stable ?
A
$$Ce$$
B
$$Eu$$
C
$$Tb$$
D
$$Dy$$
Answer :
$$Eu$$
$$E{u^{2 + }}$$ has electronic configuration $$\left[ {Xe} \right]4{f^7}$$ hence stable due to half filled atomic orbitals.
90.
In the preparation of $$KMn{O_4}$$ pyrolusite $$\left( {Mn{O_2}} \right)$$ is first converted to potassium manganate $$\left( {{K_2}Mn{O_4}} \right).$$ In this conversion, the oxidation state of manganese changes from
A
+1 to +3
B
+2 to +4
C
+3 to +5
D
+4 to +6
Answer :
+4 to +6
In $$Mn{O_2}\left( {O.S.\,\,{\text{of}}\,\,Mn\,\,{\text{is}}\, + 4} \right)\,$$ in $${K_2}Mn{O_4}\left( {O.S.\,\,{\text{of}}\,\,Mn\,\,{\text{is}}\, + 6} \right).$$ Hence $$O.S.$$ changes by 2.