Surface Chemistry & Solid State · JEE Main previous year questions

Given below are two statements for catalytic properties of transition metals. Statement I : First row transition metals which act as catalyst utilise their 3d electrons only for formation of bonds between reactant molecules and atoms on the surface of catalyst. Statement II : There is increase in the concentration of reactants on the surface of catalyst which strengthens the bonds in reacting molecules. 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 incorrect
3. C.Statement I is correct but Statement II is incorrect
4. D.Statement I is incorrect but Statement II is correct

For ${\mathrm{A}}_2+{\mathrm{B}}_2\rightleftharpoons 2AB$ ${\mathrm{E}}_{\mathrm{a}}$ for forward and backward reaction are 180 and $200\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$ respectively If catalyst lowers ${\mathrm{E}}_{\mathrm{a}}$ for both reactions by $100\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$. Which of the following statement is correct?

1. A.Catalyst does not alter the Gibbs energy change of a reaction.
2. B.The enthalpy change for the reaction is $+20\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$.
3. C.Catalyst can cause non-spontaneous reactions to occur.
4. D.The enthalpy change for the catalysed reaction is different from that of uncatalysed reaction.

Iron (III) catalyses the reaction between iodide and persulphate ions, in which A. $\mathrm{F}{\mathrm{e}}^{3+}$ oxidises the iodide ion B. $\mathrm{F}{\mathrm{e}}^{3+}$ oxidises the persulphate ion C. $\mathrm{F}{\mathrm{e}}^{2+}$ reduces the iodide ion D. $\mathrm{F}{\mathrm{e}}^{2+}$ reduces the persulphate ion Choose the most appropriate answer from the options given below:

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

While preparing crystals of Mohr's salt, dil ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ is added to a mixture of ferrous sulphate and ammonium sulphate, before dissolving this mixture in water, dil ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ is added here to :

1. A.prevent the hydrolysis of ferrous sulphate
2. B.prevent the hydrolysis of ammonium sulphate
3. C.increase the rate of formation of crystals
4. D.make the medium strongly acidic

Coagulation of egg, on heating is because of :

1. A.Denaturation of protein occurs
2. B.Biological property of protein remains unchanged
3. C.Breaking of the peptide linkage in the primary structure of protein occurs
4. D.The secondary structure of protein remains unchanged

The adsorbent used in adsorption chromatography is/are - A. silica gel B. alumina C. quick lime D. magnesia Choose the most appropriate answer from the options given below :

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

'Adsorption' principle is used for which of the following purification method?

1. A.Chromatography
2. B.Sublimation
3. C.Distillation
4. D.Extraction

Chromatographic technique/s based on the principle of differential adsorption is / are A. Column chromatography B. Thin layer chromatography C. Paper chromatography Choose the most appropriate answer from the options given below:

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

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Melting point of Boron ($2453\text{ K}$) is unusually high in group 13 elements. Reason (R) : Solid Boron has very strong crystalline lattice. In the light of the above statements, choose the most appropriate answer from the options given below ;

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

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : The diameter of colloidal particles in solution should not be much smaller than wavelength of light to show Tyndall effect. Reason R : The light scatters in all directions when the size of particles is large enough. In the light of the above statements, choose the correct answer from the options given below:

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

Sodium metal crystallizes in a body centred cubic lattice with unit cell edge length of $4\mathring{\mathrm{A}}$. The radius of sodium atom is ____ $\times 10^{-1}\mathring{\mathrm{A}}$ (Nearest integer)

Given below are two statements: Statement-I : Methane and steam passed over a heated $\mathrm{Ni}$ catalyst produces hydrogen gas. Statement-II : Sodium nitrite reacts with $\mathrm{N}{\mathrm{H}}_4\mathrm{Cl}$ to give ${\mathrm{H}}_2\mathrm{O}$, ${\mathrm{N}}_2$ and $\mathrm{NaCl}$. In the light of the above statements, choose the most appropriate answer from the options given below :

1. A.Statement I is correct but Statement II is incorrect
2. B.Both the statements I and II are incorrect
3. C.Both the statements I and II are correct
4. D.Statement I is incorrect but Statement II is correct

An atomic substance A of molar mass $12{\text{ g mol}}^{-1}$ has a cubic crystal structure with edge length of $300\text{ pm}$. The no. of atoms present in one unit cell of A is _________. (Nearest integer) Given the density of A is $3.0{\text{ g mL}}^{-1}$ and ${\mathrm{N}}_{\mathrm{A}}=6.02\times 10^{23}{\text{ mol}}^{-1}$

The number of correct statements about modern adsorption theory of heterogeneous catalysis from the following is __________ A. The catalyst is diffused over the surface of reactants. B. Reactants are adsorbed on the surface of the catalyst. C. Occurrence of chemical reaction on the catalyst's surface through formation of an intermediate. D. It is a combination of intermediate compound formation theory and the old adsorption theory. E. It explains the action of the catalyst as well as those of catalytic promoters and poisons.

$\mathrm{Mg}(\mathrm{N}{\mathrm{O}}_3{)}_2\cdot \mathrm{X}{\mathrm{H}}_2\mathrm{O}$ and $\mathrm{Ba}(\mathrm{N}{\mathrm{O}}_3{)}_2\cdot \mathrm{Y}{\mathrm{H}}_2\mathrm{O}$, represent formula of the crystalline forms of nitrate salts. Sum of X and Y is _________.

Prolonged heating is avoided during the preparation of ferrous ammonium sulphate to :

1. A.prevent hydrolysis
2. B.prevent breaking
3. C.prevent oxidation
4. D.prevent reduction

The enthalpy change for the adsorption process and micelle formation respectively are

1. A.$\Delta {\text{H}}_{\text{ads}}>0\text{ and }\Delta {\text{H}}_{\text{mic}}<0$
2. B.$\Delta {\text{H}}_{\text{ads}}>0\text{ and }\Delta {\text{H}}_{\text{mic}}>0$
3. C.$\Delta {\text{H}}_{\text{ads}}<0\text{ and }\Delta {\text{H}}_{\text{mic}}<0$
4. D.$\Delta {\text{H}}_{\text{ads}}<0\text{ and }\Delta {\text{H}}_{\text{mic}}>0$

Given below are two reactions, involved in the commercial production of dihydrogen (${\text{H}}_2$). The two reactions are carried out at temperature "${\text{T}}_1$" and "${\text{T}}_2$", respectively $$C(s)+H_{2}O(g)\stackrel{T_1}{\to }CO(g)+H_2(g)$$ $$CO(g)+H_{2}O(g)\underset{\text{Catalyst}}{\overset{T_2}{\to }}C{O}_2(g)+H_2(g)$$ The temperatures ${\text{T}}_1$ and ${\text{T}}_2$ are correctly related as :

1. A.${\text{T}}_1<{\text{T}}_2$
2. B.${\text{T}}_1={\text{T}}_2$
3. C.${\text{T}}_1=100\text{ K},{\text{T}}_2=1270\text{ K}$
4. D.${\text{T}}_1>{\text{T}}_2$

The correct relationships between unit cell edge length '$a$' and radius of sphere '$r$' for face-centred and body-centred cubic structures respectively are :

1. A.$r=2\sqrt{2}a$ and $\sqrt{3}r=4a$
2. B.$r=2\sqrt{2}a$ and $4r=\sqrt{3}a$
3. C.$2\sqrt{2}r=a$ and $\sqrt{3}r=4a$
4. D.$2\sqrt{2}r=a$ and $4r=\sqrt{3}a$

The water gas on reacting with cobalt as a catalyst forms

1. A.Methanoic acid
2. B.Methanol
3. C.Methanal
4. D.Ethanol

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

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

A compound is formed by two elements X and Y. The element Y forms cubic close packed arrangement and those of element X occupy one third of the tetrahedral voids. What is the formula of the compound?

1. A.${\text{XY}}_3$
2. B.${\text{X}}_3{\text{Y}}_2$
3. C.${\text{X}}_3\text{Y}$
4. D.${\text{X}}_2{\text{Y}}_3$

Number of crystal systems from the following where body centred unit cell can be found, is ____________. Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral, monoclinic, triclinic

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