Other Chemistry · JEE Main previous year questions

2020 54 questions

1. Q752020 · 2 Sept 2020 · Shift 1· Numerical answer

   The mass of gas adsorbed, x, per unit mass of adsorbate, m, was measured at various pressures, p. A graph between $\log \frac{x}{m}$ and $\log p$ gives a straight line with slope equal to 2 and the intercept equal to 0.4771. The value of $\frac{x}{m}$ at a pressure of 4 atm is : (Given $\log 3=0.4771$)

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   Answer: 48

2. Q542020 · 2 Sept 2020 · Shift 2
   
   1. A.$\mathrm{b}>\mathrm{c}>\mathrm{d}>\mathrm{a}$
   2. B.$\mathrm{b}>\mathrm{a}>\mathrm{c}>\mathrm{d}$
   3. C.$\mathrm{c}>\mathrm{b}>\mathrm{d}>\mathrm{a}$
   4. D.$\mathrm{c}>\mathrm{b}>\mathrm{a}>\mathrm{d}$
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   Answer: A

3. Q562020 · 2 Sept 2020 · Shift 2

   If you spill a chemical toilet cleaning liquid on your hand, your first aid would be

   1. A.aqueous $\mathrm{NaOH}$
   2. B.aqueous $\mathrm{NaHC}{\mathrm{O}}_3$
   3. C.aqueous $\mathrm{N}{\mathrm{H}}_3$
   4. D.vinegar
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   Answer: B

4. Q582020 · 2 Sept 2020 · Shift 2

   The size of a raw mango shrinks to a much smaller size when kept in a concentrated salt solution. Which one of the following processes can explain this?

   1. A.Osmosis
   2. B.Reverse osmosis
   3. C.Diffusion
   4. D.Dialysis
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   Answer: A

5. Q592020 · 2 Sept 2020 · Shift 2

   Match the type of interaction in column A with the distance dependence of their interaction energy in column B | A | B | | :--- | :--- | | (i) ion-ion | (a) $\frac{1}{r}$ | | (ii) dipole-dipole | (b) $\frac{1}{r^2}$ | | (iii) London dispersion | (c) $\frac{1}{r^3}$ | | | (d) $\frac{1}{r^6}$ |

   1. A.(I)-(a), (II)-(b), (III)-(d)
   2. B.(I)-(b), (II)-(d), (III)-(c)
   3. C.(I)-(a), (II)-(b), (III)-(c)
   4. D.(I)-(a), (II)-(c), (III)-(d)
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   Answer: D

6. Q582020 · 9 Jan 2020 · Shift 1
   
   1. A.(iii) < (i) < (ii) < (iv) < (v)
   2. B.(iii) < (iv) < (ii) < (i) < (v)
   3. C.(v) < (i) < (iv) < (ii) < (iii)
   4. D.(v) < (iii) < (ii) < (iv) < (i)
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   Answer: D

7. Q602020 · 9 Jan 2020 · Shift 1

   The acidic, basic and amphoteric oxides, respectively, are :

   1. A.$\mathrm{C}{\mathrm{l}}_2\mathrm{O}$, $\mathrm{CaO}$, ${\mathrm{P}}_4{\mathrm{O}}_{10}$
   2. B.${\mathrm{N}}_2{\mathrm{O}}_3$, $\mathrm{L}{\mathrm{i}}_2\mathrm{O}$, $\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$
   3. C.$\mathrm{MgO}$, $\mathrm{C}{\mathrm{l}}_2\mathrm{O}$, $\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$
   4. D.$\mathrm{N}{\mathrm{a}}_2\mathrm{O}$, $\mathrm{S}{\mathrm{O}}_3$, $\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$
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   Answer: B

8. Q692020 · 9 Jan 2020 · Shift 1

   'X' melts at low temperature and is a bad conductor of electricity in both liquid and solid state. X is :

   1. A.Mercury
   2. B.Carbon tetrachloride
   3. C.Zinc sulphide
   4. D.Silicon carbide
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   Answer: B

9. Q552020 · 9 Jan 2020 · Shift 2

   Which of the following has the shortest C-Cl bond?

   1. A.$\mathrm{Cl}-\mathrm{CH}=\mathrm{CH}-\mathrm{C}{\mathrm{H}}_3$
   2. B.$\mathrm{Cl}-\mathrm{CH}=\mathrm{CH}-\mathrm{N}{\mathrm{O}}_2$
   3. C.$\mathrm{Cl}-\mathrm{CH}=\mathrm{CH}-\mathrm{OC}{\mathrm{H}}_3$
   4. D.$\mathrm{Cl}-\mathrm{CH}=\mathrm{C}{\mathrm{H}}_2$
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   Answer: B

10. Q612020 · 9 Jan 2020 · Shift 2

    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
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    Answer: A

11. Q652020 · 9 Jan 2020 · Shift 2

    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.
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    Answer: C

12. Q662020 · 9 Jan 2020 · Shift 2
    
    1. A.
    2. B.
    3. C.
    4. D.
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    Answer: C

13. Q542020 · 8 Jan 2020 · Shift 1
    
    1. A.(B)
    2. B.(A)
    3. C.(C)
    4. D.(A) and (C)
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    Answer: A

14. Q572020 · 8 Jan 2020 · Shift 1

    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
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    Answer: D

15. Q582020 · 8 Jan 2020 · Shift 1

    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
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    Answer: C

16. Q592020 · 8 Jan 2020 · Shift 2

    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
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    Answer: D

17. Q642020 · 8 Jan 2020 · Shift 2

    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
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    Answer: A

18. Q752020 · 8 Jan 2020 · Shift 2· Numerical answer

    ${\mathrm{NaClO}}_3$ 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 $1\mathrm{atm},300\mathrm{K}$? ${\mathrm{NaClO}}_3(\mathrm{s})+\mathrm{Fe}(\mathrm{s})\to {\mathrm{O}}_2(\mathrm{g})+\mathrm{NaCl}(\mathrm{s})+\mathrm{FeO}(\mathrm{s})$ $\mathrm{R}=0.082{\mathrm{L}\mathrm{atm}\mathrm{mol}}^{-1}{\mathrm{K}}^{-1}$

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    Answer: 2120 to 2140

19. Q512020 · 7 Jan 2020 · Shift 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.
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    Answer: C

20. Q562020 · 7 Jan 2020 · Shift 1
    
    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.$\text{(B)}<\text{(C)}<\text{(A)}$
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    Answer: C

21. Q582020 · 7 Jan 2020 · Shift 1
    
    1. A.
    2. B.
    3. C.
    4. D.
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    Answer: A

22. Q612020 · 7 Jan 2020 · Shift 1

    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
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    Answer: D

23. Q632020 · 7 Jan 2020 · Shift 1

    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.$\mathrm{CHC}{\mathrm{l}}_3<\mathrm{C}{\mathrm{H}}_4=\mathrm{CC}{\mathrm{l}}_4$
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    Answer: B

24. Q522020 · 7 Jan 2020 · Shift 2

    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.$K_b[{\mathrm{N}}_2][{\mathrm{H}}_2\mathrm{O}{]}^2$
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    Answer: B

25. Q532020 · 7 Jan 2020 · Shift 2
    
    1. A.(C) > (B) > (A)
    2. B.(C) > (A) > (B)
    3. C.(B) > (C) > (A)
    4. D.(B) > (A) > (C)
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    Answer: A