d- and f-Block Elements · JEE Main previous year questions

The difference between spin only magnetic moment values of $[\mathrm{Co}({\mathrm{H}}_2\mathrm{O}{)}_6]\mathrm{C}{\mathrm{l}}_2$ and $[\mathrm{Cr}({\mathrm{H}}_2\mathrm{O}{)}_6]\mathrm{C}{\mathrm{l}}_3$ is ____.

Given below are two statements. Statement I : Pig iron is obtained by heating cast iron with scrap iron. Statement II : Pig iron has a relatively lower carbon content than that of cast iron. In the light of the above statements, choose the correct answer from the options given below.

1. A.Both Statement I and Statement II are correct.
2. B.Both Statement I and Statement II are not correct.
3. C.Statement I is correct but Statement II is not correct.
4. D.Statement I is not correct but Statement II is correct.

Blister copper is produced by reaction of copper oxide with copper sulphide. $2\mathrm{C}{\mathrm{u}}_2\mathrm{O}+\mathrm{C}{\mathrm{u}}_2\mathrm{S}\to 6\mathrm{Cu}+\mathrm{S}{\mathrm{O}}_2$ When $2.86\times 10^3\text{ g}$ of $\mathrm{C}{\mathrm{u}}_2\mathrm{O}$ and $4.77\times 10^3\text{ g}$ of $\mathrm{C}{\mathrm{u}}_2\mathrm{S}$ are used for reaction, the mass of copper produced is ___________ g. (nearest integer) (Atomic mass of $\mathrm{Cu}=63.5\text{ a.m. u}$, $\mathrm{S}=32.0\text{ a.m. u}$, $\mathrm{O}=16.0\text{ a.m. u}$)

Spin only magnetic moment (${\mu }_s$) of $K_3[Fe(CN{)}_6]$ is ___________ B.M. (Nearest integer)

In the metallurgical extraction of copper, following reaction is used : $\mathrm{FeO}+\mathrm{Si}{\mathrm{O}}_2\to \mathrm{FeSi}{\mathrm{O}}_3$ $\mathrm{FeO}$ and $\mathrm{FeSi}{\mathrm{O}}_3$ respectively are.

1. A.gangue and flux.
2. B.flux and slag.
3. C.slag and flux.
4. D.gangue and slag.

Acidified potassium permanganate solution oxidises oxalic acid. The spin-only magnetic moment of the manganese product formed from the above reaction is ____________ B.M. (Nearest integer)

The spin-only magnetic moment value of the most basic oxide of vanadium among ${\mathrm{V}}_2{\mathrm{O}}_3$, ${\mathrm{V}}_2{\mathrm{O}}_4$ and ${\mathrm{V}}_2{\mathrm{O}}_5$ is ________ B.M. (Nearest integer)

The metal ion (in gaseous state) with lowest spin-only magnetic moment value is :

1. A.${\mathrm{V}}^{2+}$
2. B.$\mathrm{N}{\mathrm{i}}^{2+}$
3. C.$\mathrm{C}{\mathrm{r}}^{2+}$
4. D.$\mathrm{F}{\mathrm{e}}^{2+}$

(a) Baryte, (b) Galena, (c) Zinc blende and (d) Copper pyrites. How many of these minerals are sulphide based?

If $80\mathrm{g}$ of copper sulphate $\mathrm{CuS}{\mathrm{O}}_4\cdot 5{\mathrm{H}}_2\mathrm{O}$ is dissolved in deionised water to make $5\mathrm{L}$ of solution. The concentration of the copper sulphate solution is $x\times 10^{-3}\mathrm{mol}{\mathrm{L}}^{-1}$. The value of x is ____. [Atomic masses $\mathrm{Cu}:63.54\mathrm{u}$, $\mathrm{S}:32\mathrm{u}$, $\mathrm{O}:16\mathrm{u}$, $\mathrm{H}:1\mathrm{u}$]

The spin-only magnetic moment value of $B_2^{+}$ species is ____ $\times 10^{-2}\mathrm{BM}$. (Nearest integer) [Given : $\sqrt{3}=1.73$]

The spin only magnetic moments (in BM) for free $\mathrm{T}{\mathrm{i}}^{3+}$, ${\mathrm{V}}^{2+}$ and $\mathrm{S}{\mathrm{c}}^{3+}$ ions respectively are : (At.No. Sc : 21, Ti : 22, V : 23)

1. A.3.87, 1.73, 0
2. B.1.73, 3.87, 0
3. C.1.73, 0, 3.87
4. D.0, 3.87, 1.73

1. A.Both compound 'A' and compound 'B' are dicarboxylic acids
2. B.Both compound 'A' and compound 'B' are diols
3. C.Compound 'A' is diol and compound 'B' is dicarboxylic acid
4. D.Compound 'A' is dicarboxylic acid and compound 'B' is diol

1. A.
2. B.
3. C.
4. D.

Match List - I with List - II : $$\begin{array}{llll}& \text{List - I}& & \text{List - II}\\ \text{(a)}& \text{Mercury}& \text{(i)}& \text{Vapour phase refining}\\ \text{(b)}& \text{Copper}& \text{(ii)}& \text{Distillation refining}\\ \text{(c)}& \text{Silicon}& \text{(iii)}& \text{Electrolytic refining}\\ \text{(d)}& \text{Nickel}& \text{(iv)}& \text{Zone refining}\end{array}$$ Choose the most appropriate answer from the option given below :

1. A.(a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)
2. B.(a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)
3. C.(a)-(ii), (b)-(iii), (c)-(i), (d)-(iv)
4. D.(a)-(i), (b)-(iv), (c)-(ii), (d)-(iii)

Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : Size of $\mathrm{B}{\mathrm{k}}^{3+}$ ion is less than $\mathrm{N}{\mathrm{p}}^{3+}$ ion. Reason R : The above is a consequence of the lanthanoid contraction. In the light of the above statements, choose the correct answer from the options given below :

1. A.Both A and B are true and R is the correct explanation of A
2. B.A is false but R is true
3. C.A is true but R is false
4. D.Both A and B are true but R is not the correct explanation of A

Which one of the following lanthanoids does not form $\mathrm{M}{\mathrm{O}}_2$? [M is lanthanoid metal]

1. A.Nd
2. B.Dy
3. C.Yb
4. D.Pr

1. A.
2. B.
3. C.
4. D.

Copper reduces $\mathrm{N}{\mathrm{O}}_3^{-}$ into $\mathrm{NO}$ and $\mathrm{N}{\mathrm{O}}_2$ depending upon the concentration of $\mathrm{HN}{\mathrm{O}}_3$ in solution. (Assuming fixed $[\mathrm{C}{\mathrm{u}}^{2+}]$ and ${\mathrm{P}}_{\mathrm{NO}}={\mathrm{P}}_{\mathrm{N}{\mathrm{O}}_2}$), the $\mathrm{HN}{\mathrm{O}}_3$ concentration at which the thermodynamic tendency for reduction of $\mathrm{N}{\mathrm{O}}_3^{-}$ into $\mathrm{NO}$ and $\mathrm{N}{\mathrm{O}}_2$ by copper is same is $10^x\mathrm{M}$. The value of 2x is ____. (Rounded off to the nearest integer) [Given, $E_{\mathrm{C}{\mathrm{u}}^{2+}/Cu}^o=0.34\mathrm{V}$, $E_{\mathrm{N}{\mathrm{O}}_3^{-}/NO}^o=0.96\mathrm{V}$, $E_{\mathrm{N}{\mathrm{O}}_3^{-}/N{\mathrm{O}}_2}^o=0.79\mathrm{V}$ and at $298\mathrm{K}$, $\frac{RT}{F}(2.303)=0.059$]

The spin only magnetic moment of a divalent ion in aqueous solution (atomic number 29) is _________ BM (nearest integer).

The species that has a spin-only magnetic moment of $5.9\text{ BM}$, is : ($T_d=\text{tetrahedral}$)

1. A.$[\mathrm{MnB}{\mathrm{r}}_4{]}^{2-}(T_d)$
2. B.$[\mathrm{NiC}{\mathrm{l}}_4{]}^{2-}(T_d)$
3. C.$\mathrm{Ni}(\mathrm{CO}{)}_4(T_d)$
4. D.$[\mathrm{Ni}(\mathrm{CN}{)}_4{]}^{2-}(\text{square planar})$

An acidic solution of dichromate is electrolyzed for 8 minutes using 2A current. As per the following equation $\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_7^{2-}+14{\mathrm{H}}^{+}+6{\mathrm{e}}^{-}\to 2C{\mathrm{r}}^{3+}+7{\mathrm{H}}_2\mathrm{O}$ The amount of $\mathrm{C}{\mathrm{r}}^{3+}$ obtained was $0.104\mathrm{g}$. The efficiency of the process(in%) is (Take : $\mathrm{F}=96000\mathrm{C}$, At. mass of chromium $=52$) ____.

Cast iron is used for the manufacture of :

1. A.wrought iron, pig iron and steel
2. B.wrought iron and pig iron
3. C.wrought iron and steel
4. D.pig iron, scrap iron and steel

The oxidation states of transition metal atoms in ${\mathrm{K}}_2\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_7$, $\mathrm{KMn}{\mathrm{O}}_4$ and ${\mathrm{K}}_2\mathrm{Fe}{\mathrm{O}}_4$, respectively, are x, y and z. The sum of x, y and z is _______.

Complex X of composition $\mathrm{Cr}({\mathrm{H}}_2\mathrm{O}{)}_6\mathrm{C}{\mathrm{l}}_{\mathrm{n}}$ has a spin only magnetic moment of 3.83 BM. It reacts with $\mathrm{AgN}{\mathrm{O}}_3$ and shows geometrical isomerism. The IUPAC nomenclature of X is :

1. A.Hexaaqua chromium (III) chloride
2. B.Tetraaquadichlorido chromium(IV) chloride dihydrate
3. C.Tetraaquadichlorido chromium (III) chloride dihydrate
4. D.Dichloridotetraaqua chromium (IV) chloride dihydrate