JEE MAIN - Chemistry (2023 - 29th January Morning Shift)
1
The major product 'P' for the following sequence of reactions is :
Answer
(B)
2
The magnetic behaviour of $$\mathrm{Li_2O,Na_2O_2}$$ and $$\mathrm{KO_2}$$, respectively, are :
Answer
(D)
diamagnetic, diamagnetic and paramagnetic
3
Compound that will give positive Lassaigne's test for both nitrogen and halogen is :
Answer
(C)
$$\mathrm{CH_3NH_2.HCl}$$
4
Identify the correct order for the given property for following compounds.
Choose the correct answer from the option given below :
Answer
(C)
(A), (C) and (E) only
5
The bond dissociation energy is highest for
Answer
(A)
Cl$$_2$$
6
Number of cyclic tripeptides formed with 2 amino acids A and B is :
Answer
(D)
4
7
The shortest wavelength of hydrogen atom in Lyman series is $$\lambda$$. The longest wavelength is Balmer series of He$$^+$$ is
Answer
(C)
$$\frac{9\lambda}{5}$$
8
Match List I with List II
List I
List II
Reaction
Reagents
(A)
Hoffmann Degradation
(I)
$$\mathrm{Conc. KOH}$$, $$\Delta$$
(B)
Clemenson reduction
(II)
$$\mathrm{CHCl_3,NaOH/H_3O}$$$$^ \oplus $$
(C)
Cannizaro reaction
(III)
$$\mathrm{Br_2,NaOH}$$
(D)
Reimer-Tiemann Reaction
(IV)
$$\mathrm{Zn-Hg/HCl}$$
Choose the correct answer from the options given below :
Answer
(A)
(A) - III, (B) - IV, (C) - I, (D) - II
9
The increasing order of $$\mathrm{pK_a}$$ for the following phenols is
(A) 2, 4 - Dinitrophenol
(B) 4 - Nitrophenol
(C) 2, 4, 5 - Trimethylphenol
(D) Phenol
(E) 3-Chlorophenol
Choose the correct answer from the option given below :
Answer
(D)
(A), (B), (E), (D), (C)
10
Chiral complex from the following is :
Here en = ethylene diamine
Answer
(A)
$$\mathrm{cis-[PtCl_2(en)_2]^{2+}}$$
11
The standard electrode potential $$\mathrm{(M^{3+}/M^{2+})}$$ for V, Cr, Mn & Co are $$-$$0.26 V, $$-$$0.41 V, + 1.57 V and + 1.97 V, respectively. The metal ions which can liberate $$\mathrm{H_2}$$ from a dilute acid are :
Answer
(C)
$$\mathrm{V^{2+}}$$ and $$\mathrm{Cr^{2+}}$$
12
Following chromatogram was developed by adsorption of compound 'A' on a 6 cm TLC glass plate. Retardation factor of the compound 'A' is _________ $$\times 10^{-1}$$.
Answer
6
13
Millimoles of calcium hydroxide required to produce 100 mL of the aqueous solution of pH 12 is $$x\times10^{-1}$$. The value of $$x$$ is ___________ (Nearest integer).
Assume complete dissociation.
Answer
5
14
For certain chemical reaction $$X\to Y$$, the rate of formation of product is plotted against the time as shown in the figure. The number of $$\mathrm{\underline {correct} }$$ statement/s from the following is ___________.
(A) Over all order of this reaction is one.
(B) Order of this reaction can't be determined.
(C) In region I and III, the reaction is of first and zero order respectively.
(D) In region-II, the reaction is of first order.
(E) In region-II, the order of reaction is in the range of 0.1 to 0.9.
Answer
1
15
The number of molecules or ions from the following, which do not have odd number of electrons are _________.
(A) NO$$_2$$
(B) ICl$$_4^ - $$
(C) BrF$$_3$$
(D) ClO$$_2$$
(E) NO$$_2^ + $$
(F) NO
Answer
3
16
Following figure shows dependence of molar conductance of two electrolytes on concentration. $$\Lambda \mathop m\limits^o $$ is the limiting molar conductivity.
The number of $$\mathrm{\underline {incorrect} }$$ statement(s) from the following is ___________
(A) $$\Lambda \mathop m\limits^o $$ for electrolyte A is obtained by extrapolation
(B) For electrolyte B, $$\Lambda \mathop m\limits $$ vs $$\sqrt c$$ graph is a straight line with intercept equal to $$\Lambda \mathop m\limits^o $$
(C) At infinite dilution, the value of degree of dissociation approaches zero for electrolyte B.
(D) $$\Lambda \mathop m\limits^o $$ for any electrolyte A and B can be calculated using $$\lambda^\circ$$ for individual ions
Answer
2
17
Solid Lead nitrate is dissolved in 1 litre of water. The solution was found to boil at 100.15$$^\circ$$C. When 0.2 mol of NaCl is added to the resulting solution, it was observed that the solution froze at $$-0.8^\circ$$ C. The solubility product of PbCl$$_2$$ formed is __________ $$\times$$ 10$$^{-6}$$ at 298 K. (Nearest integer)
Given : $$\mathrm{K_b=0.5}$$ K kg mol$$^{-1}$$ and $$\mathrm{K_f=1.8}$$ K kg mol$$^{-1}$$. Assume molality to the equal to molarity in all cases.
Answer
13
18
Water decomposes at 2300 K
$$\mathrm{H_2O(g)\to H_2(g)+\frac{1}{2}O_2(g)}$$
The percent of water decomposing at 2300 K and 1 bar is ___________ (Nearest integer).
Equilibrium constant for the reaction is $$2\times10^{-3}$$ at 2300 K.
Answer
2
19
Consider the following reaction approaching equilibrium at 27$$^\circ$$C and 1 atm pressure
The standard Gibb's energy change $$\mathrm{(\Delta_r G^\theta)}$$ at 27$$^\circ$$C is ($$-$$) ___________ kJ mol$$^{-1}$$ (Nearest integer).
(Given : $$\mathrm{R=8.3~J~K^{-1}~mol^{-1}}$$ and $$\mathrm{\ln 10=2.3}$$)
Answer
6
20
The sum of bridging carbonyls in $$\mathrm{W(CO)_6}$$ and $$\mathrm{Mn_2(CO)_{10}}$$ is ____________.
Answer
0
21
17 mg of a hydrocarbon (M.F. $$\mathrm{C_{10}H_{16}}$$) takes up 8.40 mL of the H$$_2$$ gas measured at 0$$^\circ$$C and 760 mm of Hg. Ozonolysis of the same hydrocarbon yields
The number of double bond/s present in the hydrocarbon is ___________.