Surface Chemistry & Solid State · JEE Main previous year questions

In a binary compound, atoms of element A form a hcp structure and those of element M occupy 2/3 of the tetrahedral voids of the hcp structure. The formula of the binary compound is :

1. A.${\mathrm{M}}_2{\mathrm{A}}_3$
2. B.${\mathrm{M}}_4{\mathrm{A}}_3$
3. C.${\mathrm{M}}_4\mathrm{A}$
4. D.$\mathrm{M}{\mathrm{A}}_3$

The charges on the colloidal $\mathrm{CdS}$ sol and $\mathrm{Ti}{\mathrm{O}}_2$ sol are, respectively :

1. A.positive and positive
2. B.positive and negative
3. C.negative and negative
4. D.negative and positive

Which of the following is Lindlar catalyst?

1. A.Partially deactivated palladised charcoal
2. B.Zinc chloride and $\mathrm{HCl}$
3. C.Sodium and Liquid $\mathrm{N}{\mathrm{H}}_3$
4. D.Cold dilute solution of $\mathrm{KMn}{\mathrm{O}}_4$

A certain element crystallises in a bcc lattice of unit cell edge length $27\text{A˚}$. If the same element under the same conditions crystallises in the fcc lattice, the edge length of the unit cell in $\text{A˚}$ will be _______. (Round off to the Nearest Integer). [Assume each lattice point has a single atom] [Assume $\sqrt{3}=1.73$, $\sqrt{2}=1.41$]

The nature of charge on resulting colloidal particles when $\mathrm{FeC}{\mathrm{l}}_3$ is added to excess of hot water is :

1. A.neutral
2. B.sometimes positive and sometimes negative
3. C.positive
4. D.negative

The number of octahedral voids per lattice site in a lattice is _________. (Rounded off to the nearest integer)

Given below are two statements : Statement I : $\alpha$ and $\beta$ forms of sulphur can change reversibly between themselves with slow heating or slow cooling. Statement II : At room temperature the stable crystalline form of sulphur is monoclinic sulphur. In the light of the above statements, choose the correct answer from the options given below :

1. A.Statement I is true but Statement II is false.
2. B.Statement I is false but Statement II is true.
3. C.Both Statement I and Statement II are true.
4. D.Both Statement I and Statement II are false.

The unit cell of copper corresponds to a face centered cube of edge length $3.596\text{A˚}$ with one copper atom at each lattice point. The calculated density of copper in $kg/{\mathrm{m}}^3$ is ____. [Molar mass of $\mathrm{Cu}:63.54\mathrm{g}$; Avogadro Number $=6.022\times 10^{23}$]

A crystal is made up of metal ions '${\mathrm{M}}_1$' and '${\mathrm{M}}_2$' and oxide ions. Oxide ions form a ccp lattice structure. The cation '${\mathrm{M}}_1$' occupies 50% of octahedral voids and the cation '${\mathrm{M}}_2$' occupies 12.5% of tetrahedral voids of oxide lattice. The oxidation numbers of '${\mathrm{M}}_1$' and '${\mathrm{M}}_2$' are, respectively :

1. A.$+3,+1$
2. B.$+4,+2$
3. C.$+1,+3$
4. D.$+2,+4$

For Freundlich adsorption isotherm, a plot of $\log (x/m)$ (y-axis) and $\log p$ (x-axis) gives a straight line. The intercept and slope for the line is 0.4771 and 2, respectively. The mass of gas, adsorbed per gram of adsorbent if the initial pressure is 0.04 atm, is ______ $\times 10^{-4}\text{ g}$. ($\log 3=0.4771$)

Tyndall effect is observed when:

1. A.The diameter of dispersed particles is similar to the wavelength of light used.
2. B.The diameter of dispersed particles is much smaller than the wavelength of light used.
3. C.The diameter of dispersed particles is much larger than the wavelength of light used.
4. D.The refractive index of dispersed phase is greater than that of the dispersion medium.

An element with molar mass $2.7\times 10^{-2}\mathrm{kg}\mathrm{mo}{\mathrm{l}}^{-1}$ forms a cubic unit cell with edge length 405 pm. If its density is $2.7\times 10^3\mathrm{kg}{\mathrm{m}}^{-3}$, the radius of the element is approximately _______ $\times 10^{-12}\mathrm{m}$ (to the nearest integer).

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

On heating compound (A) gives a gas (B) which is a constituent of air. This gas when treated with ${\mathrm{H}}_2$ in the presence of a catalyst gives another gas (C) which is basic in nature. (A) should not be :

1. A.$\mathrm{Pb}(\mathrm{N}{\mathrm{O}}_3{)}_2$
2. B.$(\mathrm{N}{\mathrm{H}}_4{)}_2\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_7$
3. C.$\mathrm{N}{\mathrm{H}}_4\mathrm{N}{\mathrm{O}}_2$
4. D.$\mathrm{Na}{\mathrm{N}}_3$

Which of the following is used for the preparation of colloids?

1. A.Van Arkel Method
2. B.Bredig’s Arc Method
3. C.Mond Process
4. D.Ostwald Process

As per Hardy-Schulze formulation, the flocculation values of the following for ferric hydroxide sol are in the order :

1. A.$\mathrm{AlC}{\mathrm{l}}_3>{\mathrm{K}}_3[\mathrm{Fe}(\mathrm{CN}{)}_6]>{\mathrm{K}}_2\mathrm{Cr}{\mathrm{O}}_4>\mathrm{KBr}=\mathrm{KN}{\mathrm{O}}_3$
2. B.${\mathrm{K}}_3[\mathrm{Fe}(\mathrm{CN}{)}_6]<{\mathrm{K}}_2\mathrm{Cr}{\mathrm{O}}_4<\mathrm{KBr}=\mathrm{KN}{\mathrm{O}}_3=\mathrm{AlC}{\mathrm{l}}_3$
3. C.${\mathrm{K}}_3[\mathrm{Fe}(\mathrm{CN}{)}_6]<{\mathrm{K}}_2\mathrm{Cr}{\mathrm{O}}_4<\mathrm{AlC}{\mathrm{l}}_3<\mathrm{KBr}<\mathrm{KN}{\mathrm{O}}_3$
4. D.${\mathrm{K}}_3[\mathrm{Fe}(\mathrm{CN}{)}_6]>\mathrm{AlC}{\mathrm{l}}_3>{\mathrm{K}}_2\mathrm{Cr}{\mathrm{O}}_4>\mathrm{KBr}>\mathrm{KN}{\mathrm{O}}_3$

Which of the following compounds is likely to show both Frenkel and Schottky defects in its crystalline form?

1. A.CsCl
2. B.AgBr
3. C.ZnS
4. D.KBr

In comparison to the zeolite process for the removal of permanent hardness, the synthetic resins method is :

1. A.less efficient as the resins cannot be regenerated.
2. B.more efficient as it can exchange only cations.
3. C.more efficient as it can exchange both cations as well as anions.
4. D.less efficient as it exchanges only anions.

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

Peptization is a :

1. A.process of converting soluble particles to form colloidal solution
2. B.process of converting precipitate into colloidal solution
3. C.process of bringing colloidal molecule into solution
4. D.process of converting a colloidal solution into precipitate

An element has a face-centred cubic (fcc) structure with a cell edge of $a$. The distance between the centres of two nearest tetrahedral voids in the lattice is :

1. A.$a$
2. B.$\frac{3}{2}a$
3. C.$\frac{a}{2}$
4. D.$\sqrt{2}a$

Among the following, the INCORRECT statement about colloids is :

1. A.The range of diameters of colloidal particles is between 1 and to 1000 nm
2. B.they are larger than small molecules and have high molar mass
3. C.They can scatter light
4. D.The osmotic pressure of a colloidal solution is of higher order than the true solution at the same concentration.

A gas undergoes physical adsorption on a surface and follows the given Freundlich adsorption isotherm equation $\frac{x}{m}=k{p}^{0.5}$ Adsorption of the gas increase with :

1. A.Decrease in p and increase in T
2. B.Increase in p and decrease in T
3. C.Decrease in p and decrease in T
4. D.Increase in p and increase in T

The aerosol is a kind of colloid in which :

1. A.solid is dispersed in gas
2. B.gas is dispersed in solid
3. C.gas is dispersed in liquid
4. D.liquid is dispersed in water

Match the catalysts (Column I) with products (Column II). $$\begin{array}{ll}\text{Column I}& \text{Column II}\\ \text{(A) }{\mathrm{V}}_2{\mathrm{O}}_5& \text{(i) Polyethylene}\\ \text{(B) }\mathrm{TiC}{\mathrm{l}}_4/Al(\mathrm{Me}{)}_3& \text{(ii) ethanal}\\ \text{(C) }\mathrm{PdC}{\mathrm{l}}_2& \text{(iii) }{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4\\ \text{(D) Iron Oxide}& \text{(iv) }\mathrm{N}{\mathrm{H}}_3\end{array}$$

1. A.(A)-(iii); (B)-(i); (C)-(ii); (D)-(iv)
2. B.(A)-(ii); (B)-(iii); (C)-(i); (D)-(iv)
3. C.(A)-(iii); (B)-(iv); (C)-(i); (D)-(ii)
4. D.(A)-(iv); (B)-(iii); (C)-(ii); (D)-(i)