Other Chemistry · JEE Main previous year questions

Reaction of one molecule of $\mathrm{HBr}$ with one molecule of 1,3-butadiene at $40^{\circ }\mathrm{C}$ gives predominantly

1. A.3-bromobutene under kinetically controlled conditions
2. B.1-bromo-2-butene under thermodynamically controlled conditions
3. C.3-bromobutene under thermodynamically controlled conditions
4. D.1-bromo-2-butene under kinetically controlled conditions

Equimolar solutions in the same solvent have

1. A.Same boiling point but different freezing point
2. B.Same freezing point but different boiling point
3. C.Same boiling and same freezing points
4. D.Different boiling and different freezing points

Hydrogen bomb is based on the principle of

1. A.Nuclear fission
2. B.Natural radioactivity
3. C.Nuclear fusion
4. D.Artificial radioactivity

A reaction involving two different reactants can never be

1. A.Unimolecular reaction
2. B.First order reaction
3. C.second order reaction
4. D.Bimolecular reaction

Amongst the following the most basic compound is

1. A.benzylamine
2. B.aniline
3. C.acetanilide
4. D.p-nitroaniline

1. A.$OCOR$
2. B.$O{C}_2{H}_5$
3. C.$N{H}_2$
4. D.$Cl$

1. A.highly spontaneous at ordinary temperature
2. B.one with negligible enthalpy change
3. C.endothermic
4. D.exothermic

Calomel ($H{g}_{2}C{l}_2$) on reaction with ammonium hydroxide gives :

1. A.$HgO$
2. B.$H{g}_{2}O$
3. C.$N{H}_2-Hg-Hg-Cl$
4. D.$HgN{H}_{2}Cl$

Which one of the following statements is NOT true about the effect of an increase in temperature on the distribution of molecular speeds in a gas?

1. A.The most probable speed increases
2. B.The fraction of the molecules with the most probable speed increases
3. C.The distribution becomes broader
4. D.The area under the distribution curve remains the same as under the lower temperature

Which of the following statements in relation to the hydrogen atom is correct?

1. A.3s orbital is lower in energy than 3p orbital
2. B.3p orbital is lower in energy than 3d orbital
3. C.3s and 3p orbitals are of lower energy than 3d orbital
4. D.3s, 3p and 3d orbitals all have the same energy

On heating mixture of $C{u}_{2}O$ and $C{u}_{2}S$ will give :

1. A.$C{u}_{2}S{O}_3$
2. B.$CuO+CuS$
3. C.$Cu+S{O}_3$
4. D.$Cu+S{O}_2$

To neutralise completely 20 mL of 0.1 M aqueous solution of phosphorous acid (${\mathrm{H}}_3\mathrm{P}{\mathrm{O}}_3$), the volume of 0.1 M aqueous KOH solution required is

1. A.40 mL
2. B.20 mL
3. C.10 mL
4. D.60 mL

Which one of the following has the regular tetrahedral structure? (Atomic nos : B = 5, S = 16, Ni = 28, Xe = 54)

1. A.$\mathrm{Xe}{\mathrm{F}}_4$
2. B.$[\mathrm{Ni}(\mathrm{CN}{)}_4{]}^{2-}$
3. C.$\mathrm{B}{\mathrm{F}}_4^{-}$
4. D.$\mathrm{S}{\mathrm{F}}_4$

The maximum number of 90° angles between bond pair of electrons is observed in

1. A.$\mathrm{ds}{\mathrm{p}}^3$ hybridization
2. B.$\mathrm{s}{\mathrm{p}}^3{\mathrm{d}}^2$ hybridization
3. C.$\mathrm{ds}{\mathrm{p}}^2$ hybridization
4. D.$\mathrm{s}{\mathrm{p}}^3\mathrm{d}$ hybridization

For the reaction, $\mathrm{CO}(\mathrm{g})+\mathrm{C}{\mathrm{l}}_2(\mathrm{g})\leftrightharpoons \mathrm{COC}{\mathrm{l}}_2(\mathrm{g})$ the $\frac{K_p}{K_c}$ is equal to :

1. A.$\sqrt{RT}$
2. B.RT
3. C.1/RT
4. D.1.0

Which one of the following statements is false?

1. A.Raoult's law states that the vapour pressure of a component over a solution is proportional to its mole fraction
2. B.Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression
3. C.The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is $\mathrm{BaC}{\mathrm{l}}_2$ > KCl > $\mathrm{C}{\mathrm{H}}_3\mathrm{COOH}$ > sucrose
4. D.The osmotic pressure ($\pi$) = MRT, where M is the molarity of the solution

The rate equation for the reaction $2A+\mathrm{B}\to \mathrm{C}$ is found to be: rate = k[A][B]. The correct statement in relation to this reaction is that the

1. A.unit of k must be ${\mathrm{s}}^{-1}$
2. B.value of k is independent of the initial concentration of A and B
3. C.rate of formation of C is twice the rate of disappearance of A
4. D.$t_{1/2}$ is a constant

Consider the following nuclear reactions ${}_{92}^{238}M\to {}_Y^{X}N+2{}_2^{4}He$ ${}_Y^{X}N\to {}_B^{A}L+2{\beta }^{+}$ The number of neutrons in the element L is

1. A.140
2. B.144
3. C.142
4. D.146

The half – life of a radioisotope is four hours. If the initial mass of the isotope was 200 g, the mass remaining after 24 hours undecayed is

1. A.1.042 g
2. B.4.167 g
3. C.3.125 g
4. D.2.084 g

Which one the following statement regarding helium is incorrect?

1. A.It is used to fill gas balloons instead of hydrogen because it is lighter and non–inflammable
2. B.It is used in gas – cooled nuclear reactors
3. C.It is used to produce and sustain powerful superconducting reagents
4. D.It is used as cryogenic agent for carrying out experiments at low temperatures

Excess of KI reacts with $\mathrm{CuS}{\mathrm{O}}_4$ solution and then $\mathrm{N}{\mathrm{a}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ solution is added to it. Which of the statements is incorrect for this reaction?

1. A.$\mathrm{C}{\mathrm{u}}_2{\mathrm{I}}_2$ is formed
2. B.Evolved ${\mathrm{I}}_2$ is reduced
3. C.$\mathrm{N}{\mathrm{a}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ is oxidized
4. D.$\mathrm{Cu}{\mathrm{I}}_2$ is formed

Acetyl bromide reacts with excess of $\mathrm{C}{\mathrm{H}}_3\mathrm{MgI}$ followed by treatment with a saturated solution of $\mathrm{N}{\mathrm{H}}_4\mathrm{Cl}$ given

1. A.acetone
2. B.acetyl iodide
3. C.2- methyl -2- propanol
4. D.acetamide

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

Among the following compounds which can be dehydrated very easily is

1. A.$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{C}(\mathrm{C}{\mathrm{H}}_3)(\mathrm{OH})\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_3$
2. B.$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{CH}(\mathrm{OH})\mathrm{C}{\mathrm{H}}_3$
3. C.$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{OH}$
4. D.$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{CH}(\mathrm{C}{\mathrm{H}}_3)\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{OH}$

As the temperature is raised from 20°C to 40°C, the average kinetic energy of neon atoms changes by a factor of which of the following?

1. A.1/2
2. B.2
3. C.$\frac{313}{293}$
4. D.$\sqrt{\frac{313}{293}}$