JEE MAIN - Chemistry (2023 - 13th April Morning Shift)
1
In which of the following processes, the bond order increases and paramagnetic character changes to diamagnetic one ?
Answer
(C)
$$\mathrm{NO} \rightarrow \mathrm{NO}^{+}$$
2
Which of the following statements are not correct?
A. The electron gain enthalpy of $$\mathrm{F}$$ is more negative than that of $$\mathrm{Cl}$$.
B. Ionization enthalpy decreases in a group of periodic table.
C. The electronegativity of an atom depends upon the atoms bonded to it.
D. $$\mathrm{Al}_{2} \mathrm{O}_{3}$$ and $$\mathrm{NO}$$ are examples of amphoteric oxides.
Choose the most appropriate answer from the options given below :
Answer
(B)
A, C and D Only
3
In the following reaction 'X' is
Answer
(B)
4
In the reaction given below
'A' is
Answer
(D)
5
The mismatched combinations are
A. Chlorophyll - Co
B. Water hardness - EDTA
C. Photography $$-\left[\mathrm{Ag}(\mathrm{CN})_{2}\right]^{-}$$
D. Wilkinson catalyst $$-\left[\left(\mathrm{Ph}_{3} \mathrm{P}\right)_{3} \mathrm{RhCl}\right]$$
E. Chelating ligand - D-Penicillamine
Choose the correct answer from the options given below :
Answer
(C)
A and C Only
6
$$\mathrm{ClF}_{5}$$ at room temperature is a:
Answer
(A)
Colourless liquid with square pyramidal geometry
7
Among the following compounds, the one which shows highest dipole moment is
Answer
(D)
8
2-Methyl propyl bromide reacts with $$\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{O}^{-}$$ and gives 'A' whereas on reaction with $$\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$$ it gives 'B'. The mechanism followed in these reactions and the products 'A' and 'B' respectively are :
The pair of lanthanides in which both elements have high third - ionization energy is :
Answer
(C)
Eu, Yb
10
In the reaction given below
'B' is
Answer
(C)
11
In the above reaction, left hand side and right hand side rings are named as '$$\mathrm{A}$$' and 'B' respectively. They undergo ring expansion. The correct statement for this process is:
Answer
(A)
Finally both rings will become six membered each.
12
The products formed in the above reaction are
Answer
(B)
One optically active and one meso product
13
The energy of an electron in the first Bohr orbit of hydrogen atom is $$-2.18 \times 10^{-18} \mathrm{~J}$$. Its energy in the third Bohr orbit is ____________.
Answer
(C)
$$\frac{1}{9}$$ th of this value
14
$$\mathrm{KMnO}_{4}$$ is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute $$\mathrm{H}_{2} \mathrm{SO}_{4}$$. Number of water molecules produced for 2 molecules of $$\mathrm{KMnO}_{4}$$ is ___________.
Answer
68
15
An organic compound gives $$0.220 \mathrm{~g}$$ of $$\mathrm{CO}_{2}$$ and $$0.126 \mathrm{~g}$$ of $$\mathrm{H}_{2} \mathrm{O}$$ on complete combustion. If the $$\%$$ of carbon is 24 then the $$\%$$ of hydrogen is __________ $$\times 10^{-1}$$. ( Nearest integer)
Answer
56
16
$$\mathrm{t}_{87.5}$$ is the time required for the reaction to undergo $$87.5 \%$$ completion and $$\mathrm{t}_{50}$$ is the time required for the reaction to undergo $$50 \%$$ completion. The relation between $$\mathrm{t}_{87.5}$$ and $$\mathrm{t}_{50}$$ for a first order reaction is $$\mathrm{t}_{87.5}=x \times \mathrm{t}_{50}$$ The value of $$x$$ is ___________. (Nearest integer)
Answer
3
17
For the given reaction
The total number of possible products formed by tertiary carbocation of A is ____________.
Answer
4
18
$$20 \mathrm{~mL}$$ of calcium hydroxide was consumed when it was reacted with $$10 \mathrm{~mL}$$ of unknown solution of $$\mathrm{H}_{2} \mathrm{SO}_{4}$$. Also $$20 \mathrm{~mL}$$ standard solution of $$0.5 ~\mathrm{M} ~\mathrm{HCl}$$ containing 2 drops of phenolphthalein was titrated with calcium hydroxide, the mixture showed pink colour when burette displayed the value of $$35.5 \mathrm{~mL}$$ whereas the burette showed $$25.5 \mathrm{~mL}$$ initially. The concentration of $$\mathrm{H}_{2} \mathrm{SO}_{4}$$ is _____________ M. (Nearest integer)
Answer
1
19
Solution of $$12 \mathrm{~g}$$ of non-electrolyte (A) prepared by dissolving it in $$1000 \mathrm{~mL}$$ of water exerts the same osmotic pressure as that of $$0.05 ~\mathrm{M}$$ glucose solution at the same temperature. The empirical formula of $$\mathrm{A}$$ is $$\mathrm{CH}_{2} \mathrm{O}$$. The molecular mass of $$\mathrm{A}$$ is __________ g. (Nearest integer)
Answer
240
20
A metal surface of $$100 \mathrm{~cm}^{2}$$ area has to be coated with nickel layer of thickness $$0.001 \mathrm{~mm}$$. A current of $$2 \mathrm{~A}$$ was passed through a solution of $$\mathrm{Ni}\left(\mathrm{NO}_{3}\right)_{2}$$ for '$$\mathrm{x}$$' seconds to coat the desired layer. The value of $$\mathrm{x}$$ is __________. (Nearest integer) ( $$\rho_{\mathrm{Ni}}$$ (density of Nickel) is $$10 \mathrm{~g} \mathrm{~mL}$$, Molar mass of Nickel is $$60 \mathrm{~g} \mathrm{~mol}^{-1}$$ $$\left.\mathrm{F}=96500 ~\mathrm{C} ~\mathrm{mol}^{-1}\right)$$
$$\mathrm{AB}, \mathrm{A}_{2}$$ and $$\mathrm{B}_{2}$$ are diatomic molecules. If the bond enthalpies of $$\mathrm{A}_{2}, \mathrm{~B}_{2}$$ and $$\mathrm{AB}$$ are in the ratio $$1: 0.5: 1$$, then the bond enthalpy of $$\mathrm{A}_{2}$$ is ____________ $$\mathrm{kJ} ~\mathrm{mol}^{-1}$$ (Nearest integer)
Answer
400
22
$$25.0 \mathrm{~mL}$$ of $$0.050 ~\mathrm{M} ~\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}$$ is mixed with $$25.0 \mathrm{~mL}$$ of $$0.020 ~\mathrm{M} ~\mathrm{NaF} . \mathrm{K}_{\mathrm{Sp}}$$ of $$\mathrm{BaF}_{2}$$ is $$0.5 \times 10^{-6}$$ at $$298 \mathrm{~K}$$. The ratio of $$\left[\mathrm{Ba}^{2+}\right]\left[\mathrm{F}^{-}\right]^{2}$$ and $$\mathrm{K}_{\mathrm{sp}}$$ is ___________.