Other Chemistry · JEE Main previous year questions

A, B and C are three biomolecules. The results of the tests performed on them are given below: $$\begin{array}{llll}& \text{Molisch’s Test}& \text{Barfoed Test}& \text{Biuret Test}\\ \text{A}& \text{Positive}& \text{Negative}& \text{Negative}\\ \text{B}& \text{Positive}& \text{Positive}& \text{Negative}\\ \text{C}& \text{Negative}& \text{Negative}& \text{Positive}\end{array}$$ A, B and C are respectively :

1. A.A = Lactose, B = Glucose, C = Albumin
2. B.A = Lactose, B = Fructose, C = Alanine
3. C.A = Lactose, B = Glucose, C = Alanine
4. D.A = Glucose, B = Fructose, C = Albumin

The true statement amongst the following is :

1. A.S is a function of temperature but $\Delta \mathrm{S}$ is not a function of temperature.
2. B.Both S and $\Delta \mathrm{S}$ are not functions of temperature.
3. C.Both $\Delta \mathrm{S}$ and S are functions of temperature.
4. D.S is not a function of temperature but $\Delta \mathrm{S}$ is a function of temperature.

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

1. A.(B)
2. B.(A)
3. C.(C)
4. D.(A) and (C)

The predominant intermolecular forces present in ethyl acetate, a liquid, are:

1. A.Dipole-dipole and hydrogen bonding
2. B.hydrogen bonding and London dispersion
3. C.London dispersion, dipole-dipole and hydrogen bonding
4. D.London dispersion and dipole-dipole

A flask contains a mixture of isohexane and 3-methylpentane. One of the liquids boils at $63^{\circ }\mathrm{C}$ while the other boils at $60^{\circ }\mathrm{C}$ What is the best way to separate the two liquids and which one will be distilled out first ?

1. A.fractional distillation, 3-methylpentane
2. B.simple distillation, 3-methylpentane
3. C.fractional distillation, isohexane
4. D.simple distillation, isohexane

Arrange the following bonds according to their average bond energies in descending order : C–Cl, C–Br, C–F, C–I

1. A.C–Br > C–I > C–Cl > C–F
2. B.C–Cl > C–Br > C–I > C–F
3. C.C–I > C–Br > C–Cl > C–F
4. D.C–F > C–Cl > C–Br > C–I

Hydrogen has three isotopes (A), (B) and (C). If the number of neutron(s) in (A), (B) and (C) respectively, are (x), (y) and (z), the sum of (x), (y) an (z) is :

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

${\mathrm{NaClO}}_3$ is used, even in spacecrafts, to produce ${\mathrm{O}}_2$. The daily consumption of pure ${\mathrm{O}}_2$ by a person is $492\mathrm{L}$ at $1\mathrm{atm},300\mathrm{K}$. How much amount of ${\mathrm{NaClO}}_3$, in grams, is required to produce ${\mathrm{O}}_2$ for the daily consumption of a person at $1\mathrm{atm},300\mathrm{K}$? ${\mathrm{NaClO}}_3(\mathrm{s})+\mathrm{Fe}(\mathrm{s})\to {\mathrm{O}}_2(\mathrm{g})+\mathrm{NaCl}(\mathrm{s})+\mathrm{FeO}(\mathrm{s})$ $\mathrm{R}=0.082{\mathrm{L}\mathrm{atm}\mathrm{mol}}^{-1}{\mathrm{K}}^{-1}$

Amongst the following statements, that which was not proposed by Dalton was :

1. A.Matter consists of indivisible atoms.
2. B.Chemical reactions involve reorganization of atoms. These are neither created nor destroyed in a chemical reaction.
3. C.When gases combine or are produced in a chemical reaction they do so in a simple ratio by volume provided all gases are at the same T & P.
4. D.All the atoms of a given element have identical properties including identical mass. Atoms of different elements differ in mass.

1. A.$\text{(A)}<\text{(B)}<\text{(C)}$
2. B.$\text{(C)}<\text{(A)}<\text{(B)}$
3. C.$\text{(B)}<\text{(A)}<\text{(C)}$
4. D.$\text{(B)}<\text{(C)}<\text{(A)}$

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

The relative strength of interionic/intermolecular forces in decreasing order is :

1. A.dipole-dipole > ion-dipole > ion-ion
2. B.ion-dipole > dipole-dipole > ion-ion
3. C.ion-dipole > ion-ion > dipole-dipole
4. D.ion-ion > ion-dipole > dipole-dipole

The dipole of $\mathrm{CC}{\mathrm{l}}_4$, $\mathrm{CHC}{\mathrm{l}}_3$ and $\mathrm{C}{\mathrm{H}}_4$ are in the order :

1. A.$\mathrm{CC}{\mathrm{l}}_4<\mathrm{C}{\mathrm{H}}_4<\mathrm{CHC}{\mathrm{l}}_3$
2. B.$\mathrm{C}{\mathrm{H}}_4=\mathrm{CC}{\mathrm{l}}_4<\mathrm{CHC}{\mathrm{l}}_3$
3. C.$\mathrm{C}{\mathrm{H}}_4<\mathrm{CC}{\mathrm{l}}_4<\mathrm{CHC}{\mathrm{l}}_3$
4. D.$\mathrm{CHC}{\mathrm{l}}_3<\mathrm{C}{\mathrm{H}}_4=\mathrm{CC}{\mathrm{l}}_4$

For the reaction $$2{\mathrm{H}}_2(g)+2\mathrm{NO}(g)\to {\mathrm{N}}_2(g)+2{\mathrm{H}}_2\mathrm{O}(g)$$ the observed rate expression is, $\text{rate}=K_f[\mathrm{NO}{]}^2[{\mathrm{H}}_2]$. The rate expression for the reverse reaction is :

1. A.$K_b[{\mathrm{N}}_2][{\mathrm{H}}_2\mathrm{O}]$
2. B.$K_b[{\mathrm{N}}_2][{\mathrm{H}}_2\mathrm{O}{]}^2/[{\mathrm{H}}_2]$
3. C.$K_b[{\mathrm{N}}_2][{\mathrm{H}}_2\mathrm{O}{]}^2/[\mathrm{NO}]$
4. D.$K_b[{\mathrm{N}}_2][{\mathrm{H}}_2\mathrm{O}{]}^2$

1. A.(C) > (B) > (A)
2. B.(C) > (A) > (B)
3. C.(B) > (C) > (A)
4. D.(B) > (A) > (C)

The equation that is incorrect is :

1. A.$({\Lambda }_m^0{)}_{KCl}-({\Lambda }_m^0{)}_{NaCl}=({\Lambda }_m^0{)}_{KBr}-({\Lambda }_m^0{)}_{NaBr}$
2. B.$({\Lambda }_m^0{)}_{NaBr}-({\Lambda }_m^0{)}_{NaI}=({\Lambda }_m^0{)}_{KBr}-({\Lambda }_m^0{)}_{NaBr}$
3. C.$({\Lambda }_m^0{)}_{NaBr}-({\Lambda }_m^0{)}_{NaCl}=({\Lambda }_m^0{)}_{KBr}-({\Lambda }_m^0{)}_{KCl}$
4. D.$({\Lambda }_m^0{)}_{H_{2}O}=({\Lambda }_m^0{)}_{HCl}+({\Lambda }_m^0{)}_{NaOH}-({\Lambda }_m^0{)}_{NaCl}$

Which of the following statements is correct ?

1. A.Gluconic acid can form cyclic (acetal/hemiacetal) structure
2. B.Gluconic acid is a partial oxidation product of glucose
3. C.Gluconic acid is obtained by oxidation of glucose with ($\mathrm{HN}{\mathrm{O}}_3$)
4. D.Gluconic acid is a dicarboxylic acid.

1. A.$A-V_{\text{av}};B-V_{\text{rms}};C-V_{\text{mp}}$
2. B.$A-V_{\text{rms}};B-V_{\text{mp}};C-V_{\text{av}}$
3. C.$A-V_{\text{mp}};B-V_{\text{av}};C-V_{\text{rms}}$
4. D.$A-V_{\text{mp}};B-V_{\text{rms}};C-V_{\text{av}}$

The flocculation value of HCl for arsenic sulphide sol. is $30{\text{ m mol L}}^{-1}$ If ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ is used for the flocculation of arsenic sulphide, the amount in grams, of ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ in 250 ml required for the above purpose is _______. (molecular mass of ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4=98\text{ g/mol}$)

1. A.$\text{(C)}<\text{(A)}<\text{(D)}<\text{(B)}$
2. B.$\text{(B)}<\text{(D)}<\text{(C)}<\text{(A)}$
3. C.$\text{(B)}<\text{(D)}<\text{(A)}<\text{(C)}$
4. D.$\text{(A)}<\text{(C)}<\text{(D)}<\text{(B)}$

The correct statement among the following is :

1. A.$({\text{SiH}}_3{)}_3\text{N}$ is planar and more basic than $({\text{CH}}_3{)}_3\text{N}$
2. B.$({\text{SiH}}_3{)}_3\text{N}$ is pyramidal and more basic than $({\text{CH}}_3{)}_3\text{N}$
3. C.$({\text{SiH}}_3{)}_3\text{N}$ is pyramidal and less basic than $({\text{CH}}_3{)}_3\text{N}$
4. D.$({\text{SiH}}_3{)}_3\text{N}$ is planar and less basic than $({\text{CH}}_3{)}_3\text{N}$

The metal that gives hydrogen gas upon treatment with both acid as well as base is :

1. A.mercury
2. B.zinc
3. C.iron
4. D.magnesium

Thermal decomposition of a Mn compound (X) at 513 K results in compound Y, ${\text{MnO}}_2$ and gaseous product. ${\text{MnO}}_2$ reacts with NaCl and concentrated ${\text{H}}_2{\text{SO}}_4$ to give a pungent gas Z. X, Y and Z, respectively, are :

1. A.${\text{KMnO}}_4$, ${\text{K}}_2{\text{MnO}}_4$ and ${\text{Cl}}_2$
2. B.${\text{K}}_2{\text{MnO}}_4$, ${\text{KMnO}}_4$ and ${\text{SO}}_2$
3. C.${\text{K}}_3{\text{MnO}}_4$, ${\text{K}}_2{\text{MnO}}_4$ and ${\text{Cl}}_2$
4. D.${\text{K}}_2{\text{MnO}}_4$, ${\text{KMnO}}_4$ and ${\text{Cl}}_2$

The INCORRECT match in the following is :

1. A.$\Delta {\text{G}}^{\circ }=0$, $\text{K}=1$
2. B.$\Delta {\text{G}}^{\circ }<0$, $\text{K}<1$
3. C.$\Delta {\text{G}}^{\circ }>0$, $\text{K}<1$
4. D.$\Delta {\text{G}}^{\circ }<0$, $\text{K}>1$