d and f Block Elements
327 Questions
Start JEE Mains Test
2008
Q301
JEE Mains
MCQ
14 Mar 2026
Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the
main reason being :
A.
4f orbitals more diffused than the 5f orbitals
B.
lesser energy difference between 5f and 6d than between 4f and 5d orbitals
C.
more energy difference between 5f and 6d than between 4f and 5d orbitals
D.
more reactive nature of the actinoids than the lanthanoids
2007
Q302
JEE Mains
MCQ
14 Mar 2026
The actinoids exhibits more number of oxidation states in general than the lanthanoids. This is
because :
A.
the 5f orbitals are more buried than the 4f orbitals
B.
there is a similarity between 4f and 5f orbitals in their angular part of the wave function
C.
the actinoids are more reactive than the lanthanoids
D.
the 5f orbitals extend further from the nucleus than the 4f orbitals
2007
Q303
JEE Mains
MCQ
14 Mar 2026
Identify the incorrect statement among the following :
A.
d-Block elements show irregular and erratic chemical properties among themselves
B.
La and Lu have partially filled d orbitals and no other partially filled orbitals
C.
The chemistry of various lanthanoids is very similar
D.
4f and 5f orbitals are equally shielded
2006
Q304
JEE Mains
MCQ
14 Mar 2026
Lanthanoid contraction is caused due to :
A.
the appreciable shielding on outer electrons by 4f electrons from the nuclear charge
B.
the appreciable shielding on outer electrons by 5d electrons from the nuclear charge
C.
the same effective nuclear charge from Ce to Lu
D.
the imperfect shielding on outer electrons by 4f electrons from the nuclear charge
2006
Q305
JEE Mains
MCQ
14 Mar 2026
A metal, $M$ forms chlorides in its $+2$ and $+4$ oxidation states. Which of the following statements about these chlorides is correct?
A.
$MC{l_2}$ is more ionic than $MC{l_4}$
B.
$MC{l_2}$ is more easily hydrolysed than $MC{l_4}$
C.
$MC{l_2}$ is more volatile than $MC{l_4}$
D.
$MC{l_2}$ is more soluble in anhydrous ethanol than $MC{l_4}$.
2006
Q306
JEE Mains
MCQ
14 Mar 2026
The “spin-only” magnetic moment [in units of Bohr magneton, (µB)] of Ni2+ in aqueous solution would
be : (Atomic number of Ni = 28)
A.
2.84
B.
4.90
C.
0
D.
1.73
2005
Q307
JEE Mains
MCQ
14 Mar 2026
On heating mixture of $C{u_2}O$ and $C{u_2}S$ will give :
A.
$C{u_2}S{O_3}$
B.
$CuO + CuS$
C.
$Cu + S{O_3}$
D.
$Cu + S{O_2}$
2005
Q308
JEE Mains
MCQ
14 Mar 2026
Calomel $\left( {H{g_2}C{l_2}} \right)$ on reaction with ammonium hydroxide gives :
A.
$HgO$
B.
$H{g_2}O$
C.
$N{H_2} - Hg - Hg - Cl$
D.
$HgN{H_2}Cl$
2005
Q309
JEE Mains
MCQ
14 Mar 2026
The oxidation state of chromium in the final product formed the reaction between $K{\rm I}$ and acidified potassium dichromate solution is :
A.
$+3$
B.
$+2$
C.
$+6$
D.
$+4$
2005
Q310
JEE Mains
MCQ
14 Mar 2026
Which of the following factors may be regarded as the main cause of lanthanide
contraction?
A.
Poor shielding of one of 4f electron by another in the subshell
B.
Effective shielding of one of 4f electrons by another in the subshell
C.
Poorer shielding of 5d electrons by 4f electrons
D.
Greater shielding of 5d electrons by 4f electrons
2005
Q311
JEE Mains
MCQ
14 Mar 2026
The lanthanide contraction is responsible for the fact that :
A.
Zr and Y have about the same radius
B.
Zr and Nb have similar oxidation
state
C.
Zr and Hf have about the same radius
D.
Zr and Zn have the same oxidation
2005
Q312
JEE Advanced
Numerical
14 Mar 2026
Write the balanced chemical equation for developing a back and white photographic film. Also explain why the solution of sodium thiosulphate on acidification turns milky white.
Correct Answer: <img src="https://app-content.cdn.examgoal.net/fly/@width/image/jaoe38c1mh9ldbp4/f600a80f-fe31-436e-8860-9965dc610b3d/b526df80-b373-11f0-b034-2711d08df967/file-jaoe38c1mh9ldbp5.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/jaoe38c1mh9ldbp4/f600a80f-fe31-436e-8860-9965dc610b3d/b526df80-b373-11f0-b034-2711d08df967/file-jaoe38c1mh9ldbp5.png" loading="lazy" style="max-width:100%;height:auto;display:block;margin:0 auto;max-height:40vh;vertical-align:baseline" alt="IIT-JEE 2005 Mains Chemistry - d and f Block Elements Question 3 English Answer">
Explanation:
In the development of photographic film, the black and white photographic film is developed as follows:
The silver bromide reacts with hydroquinone producing black coloured silver particles along with HBr and quinone. During this process, silver bromide gets reduced to silver and hydroquinone is oxidised to quinone.
The hydroquinone acts as a developer during this process.
The unreacted silver bromide then reacts with sodium thiosulphate to produce soluble complex and sodium bromide.
$\mathrm{AgBr + \mathop {2N{a_2}{S_2}{O_3}}\limits_{hypo\,solution} \to \mathop {N{a_3}[Ag{{({S_2}{O_3})}_2}]}\limits_{so{\mathop{\rm lub}} le} + NaBr}$
The reaction occurs in acidic medium. In acidic medium, sulphur from sodium thiosulphate will precipitate out. The colloidal sulphur is obtained which gives milky white turbidity.
$\mathrm{Na}_2 \mathrm{~S}_2 \mathrm{O}_3+2 \mathrm{H}^{+}(a q) \longrightarrow 2 \mathrm{Na}^{+}+\mathrm{H}_2 \mathrm{SO}_3+\underset{\substack{\text { colloidal } \\ \text { sulphur }}}{\mathrm{S} \downarrow}$
Final Answer :
$\mathrm{AgBr + \mathop {2N{a_2}{S_2}{O_3}}\limits_{hypo\,solution} \to \mathop {N{a_3}[Ag{{({S_2}{O_3})}_2}]}\limits_{so{\mathop{\rm lub}} le} + NaBr}$
2004
Q313
JEE Mains
MCQ
14 Mar 2026
Of the following outer electronic configurations of atoms, the highest oxidation state is achieved by which one of them?
A.
$\left( {n - 1} \right){d^3}n{s^2}$
B.
$\left( {n - 1} \right){d^5}n{s^1}$
C.
$\left( {n - 1} \right){d^8}n{s^2}$
D.
$\left( {n - 1} \right){d^5}n{s^2}$
2004
Q314
JEE Mains
MCQ
14 Mar 2026
Cerium (Z = 58) is an important member of the lanthanoids. Which of the following
statements about cerium is incorrect?
A.
The common oxidation states of cerium are +3 and +4
B.
Cerium (IV) acts as an oxidizing agent
C.
The +4 oxidation state of cerium is not known in solutions
D.
The +3 oxidation state of cerium is more stable than the +4 oxidation state
2004
Q315
JEE Mains
MCQ
14 Mar 2026
Excess of KI reacts with CuSO4 solution and then Na2S2O3 solution is added to it. Which of the statements is incorrect for this reaction?
A.
Cu2I2 is reduced
B.
Evolved I2 is reduced
C.
Na2S2O3 is oxidized
D.
CuI2 is formed
2003
Q316
JEE Mains
MCQ
14 Mar 2026
What would happen when a solution of potassium chromate is treated with an excess of dilute nitric acid?
A.
$Cr_2O^{2-}_7$ and H2O are formed
B.
$CrO^{2-}_4$ is reduced to +3 state of Cr
C.
$CrO^{2-}_4$ is oxidized to +7 state of Cr
D.
Cr3+ and $Cr_2O^{2-}_7$ are formed
2003
Q317
JEE Mains
MCQ
14 Mar 2026
The number of d-electrons retained in Fe2+ (At no of Fe = 26) ion is :
A.
4
B.
5
C.
6
D.
3
2003
Q318
JEE Mains
MCQ
14 Mar 2026
A red solid is insolvable in water. However it becomes soluble if some $K{\rm I}$ is added to water. Heating the red solid in a test tube results in liberation of some violet colored fumes and droplets of a metal appear on the cooler parts of the test tube. The red solid is :
A.
$Hg{{\rm I}_2}$
B.
$HgO$
C.
$P{b_3}{O_4}$
D.
${\left( {N{H_4}} \right)_2}C{r_2}{O_7}$
2003
Q319
JEE Mains
MCQ
14 Mar 2026
Which one of the following statements is correct?
A.
From a mixed precipitate of AgCl and AgI, ammonia solution dissolves only AgCl
B.
Ferric ions give a deep green precipitate on adding potassium ferrocyanide solution
C.
On boiling a solution having K+, Ca2+ and HCO3 ions we get a precipitate of K2Ca(CO3)2.
D.
Manganese salts give a violet borax bead test in the reducing flame
2003
Q320
JEE Mains
MCQ
14 Mar 2026
Which one of the following nitrates will leave behind a metal on strong heating?
A.
Copper nitrate
B.
Manganese nitrate
C.
Silver nitrate
D.
Ferric nitrate
2003
Q321
JEE Mains
MCQ
14 Mar 2026
The atomic numbers of vanadium (V), Chromium (Cr), manganese (Mn) and iron (Fe) are respectively 23, 24, 25 and 26. Which one of these may be expected to have the highest second ionization enthalpy?
A.
Cr
B.
Mn
C.
Fe
D.
V
2003
Q322
JEE Mains
MCQ
14 Mar 2026
For making good quality mirrors, plates of float glass are used. These are obtained by floating molten glass
over a liquid metal which does not solidify before glass. The metal used can be :
A.
tin
B.
sodium
C.
magnesium
D.
mercury
2003
Q323
JEE Mains
MCQ
14 Mar 2026
The radius of La3+ (Atomic number of La = 57) is 1.06 Å. Which one of the following given values will be
closest to the radius of Lu3+ (Atomic number of Lu = 71) ?
A.
1.60 Å
B.
1.40 Å
C.
0.85 Å
D.
1.60 Å
2002
Q324
JEE Mains
MCQ
14 Mar 2026
How do we differentiate between Fe3+ and Cr3+ in group III?
A.
by taking excess of NH4OH solution
B.
by increasing $NH_4^+$ ion concentration
C.
by decreasing OH- ion concentration
D.
both (b) and (c)
2002
Q325
JEE Mains
MCQ
14 Mar 2026
Most common oxidation states of Ce (cerium) are :
A.
+3, +4
B.
+2, +3
C.
+2, +4
D.
+3, +5
2002
Q326
JEE Mains
MCQ
14 Mar 2026
When KMnO4 acts as an oxidising agent and ultimately forms [MnO4]-2, MnO2, Mn2O3, Mn+2
then the number of electrons transferred in each case respectively is :
A.
4, 3, 1, 5
B.
1, 5, 3, 7
C.
1, 3, 4, 5
D.
3, 5, 7, 1
2002
Q327
JEE Mains
MCQ
14 Mar 2026
Which of the following ions has the maximum magnetic moment?
A.
Mn2+
B.
Fe2+
C.
Ti2+
D.
Cr2+