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.
201.
Which of the following lanthanide ion is paramagnetic?
202.
If $$KMn{O_4}$$ is reduced by oxalic acid in an acidic medium then oxidation number of $$Mn$$ changes from
A
4 to 2
B
6 to 4
C
+7 to +2
D
7 to 4
Answer :
+7 to +2
In acid medium
$$MnO_4^ - + 8{H^ + } + 5{e^ - } \to M{n^{2 + }} + 4{H_2}O$$
( $$O.S.$$ of $$Mn$$ changes form +7 to +2 ).
203.
More number of oxidation states are exhibited by the actinides than by the lanthanides. The main reason for this is
A
more energy difference between $$5f$$ and $$6d$$ - orbitals than that between $$4f$$ and $$5d$$ - orbitals
B
lesser energy difference between $$5f$$ and $$6d$$ - orbitals than that between $$4f$$ and $$5d$$ - orbitals
C
greater metallic character of the lanthanides than that of the corresponding actinides
D
more active nature of the actinides
Answer :
lesser energy difference between $$5f$$ and $$6d$$ - orbitals than that between $$4f$$ and $$5d$$ - orbitals
More number of oxidation states are exhibited by the actinides than by the corresponding lanthanides due to lesser energy difference between $$5f$$ and $$6d$$ orbitals than that between $$4f$$ and $$5d$$ - orbitals.
204.
In which of the following pairs of ions, the higher oxidation state in aqueous solution is more stable than the other?
$$\eqalign{
& \left( {\text{i}} \right)T{l^ + },T{l^{3 + }} \cr
& \left( {{\text{ii}}} \right)C{u^ + },C{u^{2 + }} \cr
& \left( {{\text{iii}}} \right)C{r^{2 + }},C{r^{3 + }} \cr
& \left( {{\text{iv}}} \right){V^{2 + }},V{O^{2 + }} \cr} $$
A
(i), (ii)
B
(ii), (iii)
C
(ii), (iv)
D
(ii), (iii), (iv)
Answer :
(ii), (iii), (iv)
No explanation is given for this question. Let's discuss the answer together.
205.
Which one is solder?
A
$$Cu\,\& \,Pb$$
B
$$Zn\,\& Cu$$
C
$$Pb\,\& \,Sn$$
D
$$Fe\,\& \,Zn$$
Answer :
$$Pb\,\& \,Sn$$
Solder is an alloy containing $$Sn - 67\% \,\,{\text{and}}\,\,Pb - 33\% .$$
206.
Which of the following pairs of ions have the same electronic configuration?
207.
The soldiers of Napolean army while at Alps during freezing winter suffered a serious problem as regards to the tin buttons of their uniforms. White metallic tin buttons got converted to grey power. This transformation is related to
A
a change in the partial pressure of oxygen in the air
B
a change in the crystalline structure of tin
C
an interaction with nitrogen of the air at very low temperature
D
an interaction with water vapour contained in the humid air
Answer :
a change in the crystalline structure of tin
$${\text{Grey tin}} \rightleftharpoons {\text{white tin }}$$
Grey tin is brittle and crumbles down to powder in very cold climate
The conversion of grey tin to white tin is acompained by increase in volume. This is known as tin plaque or tin disease.
208.
Which of the following statements for the reaction, is correct?
$$N{a_2}Cr{O_4} + {H_2}S{O_4} \to $$
A
It is a redox reaction in which green solution of $${\left[ {Cr{{\left( {{H_2}O} \right)}_6}} \right]^{ + 3}}$$ is produced.
B
One of the product in reaction has trigonal planar structure.
C
Dimeric bridged tetrahedral metal ion is produced.
D
Dark blue colour is obtained in reaction.
Answer :
Dimeric bridged tetrahedral metal ion is produced.
209.
Number of electrons transfered in each case when $$KMn{O_4}$$ acts as an oxidising agent to give $$Mn{O_2},M{n^{2 + }},Mn{\left( {OH} \right)_3}$$ and $$MnO_4^{2 - }$$ are respectively
A
3, 5, 4 and 1
B
4, 3, 1 and 5
C
1, 3, 4 and 5
D
5, 4, 3 and 1
Answer :
3, 5, 4 and 1
210.
Chloro compound of Vanadium has only spin magnetic moment of $$1.73\,BM.$$ This Vanadium chloride has the formula :
A
$$VC{l_2}$$
B
$$VC{l_4}$$
C
$$VC{l_3}$$
D
$$VC{l_5}$$
Answer :
$$VC{l_4}$$
$$\eqalign{
& \mu = \sqrt {n\left( {n + 2} \right)} \cr
& 1.73 = \sqrt {n\left( {n + 2} \right)} \cr} $$
On calculating the value of $$n$$ we find $$n = 1$$
No. of unpaired electrons $$= 1$$
hence its configuration will be
$$\eqalign{
& V\left( {23} \right) = \left[ {Ar} \right]3{d^3}4{s^2} \cr
& {V^{4 + }} = \left[ {Ar} \right]3{d^1} \cr} $$
∴ Its chloride has the formula $$VC{l_4}$$