AIIMS 2019

Assertion : Tert-butyl methyl ether react with \(\mathrm{HBr}\) to form tert butyl, \(\left(\mathrm{CH}_3\right)_3 \mathrm{C}-\mathrm{Br}\) and \(\mathrm{CH}_3-\mathrm{OH}\), methanal.
Reason : It follows \(\mathrm{S}_{\mathrm{N}} 1\) mecha...

Assertion : Phenol reacts with \(\mathrm{CH}_3 \mathrm{I}\) in presence of \(\mathrm{NaOH}\) to form methoxybenzene.
Reason : Phenoxide is better nucleophile than phenol.

Find out the products of reaction

Assertion : Anhydrides are more reactive than ester for nucleophilic substitution.
Reason : \(RCOO -\) is better leaving group than \(\mathrm{R}-\mathrm{O}^{-}\).

Assertion : Two sugar units joined by 1, 2-glycosidic bond in sucrose.
Reason : It contains \(\mathrm{C}_1\)-glucose and \(\mathrm{C}_2\)-fructose glycosidic bond.

Assertion : Glucose does not gives 2, 4- DNP
test.
Reason : Glucose exists in cyclic hemiacetal
form.

Assertion : Tryptophan is an example of
non-essential amino acids.
Reason : The amino acids that are not
synthesised in human body are
non-essential amino acids.

Which of the following, number of lone pair at central atom zero \(\mathrm{XeO}_3, \mathrm{XeO}_2 \mathrm{~F}_2, \mathrm{XeO}_4, \mathrm{XeO}_3 \mathrm{~F}_2, \mathrm{XeF}_6\) ?

Which is least soluble?

Assertion : \(\mathrm{BO}_3^{-3}\) and \(\mathrm{SO}_3^{-2}\) are not isostructural. Reason : In \(\mathrm{SO}_3^{2-}\) sulphur has one lone pair of electron.

Find out time period of Ist order reaction. When reaction complete \(2 / 3 \mathrm{rd}\). If the value of rate constant is \(4.3 \times 10^{-4}\)

What is the activation energy \((\mathrm{kJ} / \mathrm{mol})\) for a reaction if its rate constant doubles when the temperature is raised from \(300 \mathrm{~K}\) to \(400 \mathrm{~K}\) of these $$(R=8.314 \mathrm{~Jmol}^{-1} \mathrm{~K}^{-...

Assertion : For liquid dishwashing
non-ionic type of detergent are used.
Reason : Remove grease and oil by micelle
formation.

\(\left[\mathrm{Co}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]^{3-}\) is a

Correct increasing order for the wavelength of absorption in the visible region for the complexes of \(\mathrm{Co}^{3+}\) is

Which of the following complex is optically
inactive?

Which element can have oxidation state
from 4 to 6?

Which give coloured carbonate precipitate?

Assertion : Out of \(\mathrm{CrO}_3\) and \(\mathrm{Al}_2 \mathrm{O}_3, \mathrm{CrO}_3\) having lower melting point than \(\mathrm{Al}_2 \mathrm{O}_3\).
Reason : Oxidation state of \(\mathrm{Cr}\) in \(\mathrm{CrO}_3\) is high.

Assertion : \(\mathrm{S}_2 \mathrm{O}_7^{2-}\) and \(\mathrm{Cr}_2 \mathrm{O}_7^{2-}\) both exist.
Reason : Both have same valence electrons.

Assertion : \(\mathrm{Yb}^{2+}\) is more stable in compare to \(\mathrm{Gd}^{+2}\).
Reason : The electronic configuration of GD is \([\mathrm{Xe}] 4 f^7 5 d^2 6 s^2\).

Assertion : \(d^5\) configuration is more stable than \(d^4\).
Reason : \(d^5\) has more exchange energy as compared to \(d^4\) because 10 and 6 exchanges are possible in \(d^5\) and \(d^4\) respectively.

Cell notation, $$\begin{gathered} M\left|M^{2+} \| M^{2+}\right| M. \\ 0.01 \quad 0.0001 \end{gathered}$$ If value of \(E^{\circ}{ }_{\text {cell }} \text { is } 4 \text { volt ( Given } \frac{R T}{F} \text { in } 10=0.06 \text { ) }\)

Assertion : The graph between \(p V\) v/s \(\frac{1}{V}\) is a straight line.
Reason : For adiabatic process, \(p \propto \frac{1}{V}\)

Correct order for reaction with alcoholic KOH

Correct order of electrophillic substitution
reaction is

Assertion : Propene reacts with \(\mathrm{HI}\) in presence of peroxide give 1-iodopropane.
Reason : \(1^{\circ}\) free radical is less stable than \(2^{\circ}\) free radical.

Yellow colour of chlorine water fades because of

\(\mathrm{H}_2 \mathrm{O}_2\) is obtained by which of the following?

\(\mathrm{pH}\) of a salt solution of weak acid \((\mathrm{p} K_a=4)\) and weak base \((\mathrm{p} K_b=5)\) at \(25^{\circ}\) is

Assertion : Tert-butyl amine can be formed by Gabriel phthalimide synthesis.
Reason : It follow \(\mathrm{S}_{\mathrm{N}} 1\) mechanism.

Which of the following statement is correct
for oleum?

Which of the following inert gas participate
in chemical reaction?

Correct order of bond dissociation energy

Which have melting point below \(500^{\circ} \mathrm{C}\) ?

Which has least covalent radius?

Which pair of elements has maximum
electronegativity difference?

Match the following columns.

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Assertion : Nylon-6 is condensation polymer.
Reason : It is polymer of caprolactum.

Which of the following has maximum iron
content?

Which of the following can react with \(\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7\) ?

Out of \(\mathrm{BeF}_2, \mathrm{MgF}_2, \mathrm{CaF}_2, \mathrm{SrF}_2\) which has maximum solubility?

The tetrahedral voids are present in 0.5 mole of hcp crystal structure

Which of the following is correct order of
packing efficiency?

Assertion : ZnO becomes yellow when it is
heated.
Reason : The anionic sites occupied by
unpaired electrons (due to F-centres).

The vapour pressure of pure \(\mathrm{CHCl}_3\) and \(\mathrm{CH}_2 \mathrm{Cl}_2\) are 200 and \(41.5 \mathrm{~atm}\) respectively. The weight of \(\mathrm{CHCl}_3\) and \(\mathrm{CH}_2 \mathrm{Cl}_2\) are respectively \(11.9 \mathrm{~g}\)...

If boiling point of water is \(100^{\circ} \mathrm{C}\). How much gram of \(\mathrm{NaCl}\) is added in \(500 \mathrm{~g}\) of water to increase its boiling point of water by approx $$1^{\circ} \mathrm{C}\left(K_b\right)_{\mathrm{H}_2 \math...

Find empirical formula of the compound if \(M=68 \%\) (atomic mass \(=34\) ) and remaining \(32 \%\) oxygen.

Order of acidic nature

Compare stability of free radicals
(I) \(\mathrm{CH}_3-\mathop C\limits^ \bullet H-\mathrm{CH}_3\)
(II)
(III) \(\mathop C\limits^ \bullet {H_2}-\mathrm{CH}\left(\mathrm{CH}_3\right)_2\)
(IV) $$\mathop C\limits^ \bullet {H_2}-\mathrm{CH}...