Practice Questions

Q51.Consider the following reactions NiS + HNO3 + HCl →A + NO + S + H2O A + NH4OH + H3C −C = N −OH | →B + NH4Cl + H2O The number of protons that do not involve in H3C −C = N −OH hydrogen bonding in the product B is ______.

Q51.Frequency of the de-Broglie wave of electron in Bohr's first orbit of hydrogen atom is _______ ×1013 Hz [Given : RH( Rydberg constant ) = 2.18 × 10−18 J, h (Plank's (nearest integer). constant ) = 6.6 × 10−34 J.s.]

Q52.The number of species from the following which are paramagnetic and with bond order equal to one is H2, He+2 , O+2 , N2−2 , O2−2 , F2, Ne+2 , B2

Q53.An ideal gas, Cv = 2 R, is expanded adiabatically against a constant pressure of 1 atm untill it doubles in volume. If the initial temperature and pressure is 298 K and 5 atm, respectively then the final temperature is – _______ K (nearest integer). [ Cv is the molar heat capacity at constant volume] JEE Main 2024 (06 Apr Shift 1) JEE Main Previous Year Paper ′′ −

Q55.Total number of aromatic compounds among the following compounds is ______.

Q55.Consider the dissociation of the weak acid HX as given below HX(aq) ⇌H+(aq) + X−(aq), Ka = 1.2 × 10−5 [Ka : dissociation constant ] The osmotic pressure of 0.03M aqueous solution of HX at 300 K is _______ ×10−2 bar (nearest integer). [Given : R = 0.083 Lbarmol−1 K−1 ]

Q55.How many compounds among the following compounds show inductive, mesomeric as well as hyperconjugation effects?

Q55.Considering acetic acid dissociates in water, its dissociation constant is 6.25 × 10−5 . If 5 mL of acetic acid is dissolved in 1 litre water, the solution will freeze at −x × 10−2∘C, provided pure water freezes at 0∘C. x = (Kf)water = 1.86 K kg mol−1. density of acetic acid is 1.2 g mol−1. ______ . (Nearest integer) Given : molar mass of water = 18 g mol−1. Acetic acid dissociates as molar mass of acetic acid=60 gmol−1. density of water = 1 g cm−3 CH3COOH ⇌CH3COO⊖+ H⊕

Q57.Consider the following redox reaction: MnO4- + H+ + H2C2O4 ⇌Mn2 + + H2O + CO2 The standard reduction potentials are given as below Ered° E0 = + 1 . 51 V; E0 = - 0 . 49 V CO2 / H2C2O4 MnO4- / Mn2 + If the equilibrium constant of the above reaction is given as Keq = 10x, then the value of x = _______ (nearest integer)

Q57.Among CrO, Cr2O3 and CrO3 , the sum of spin-only magnetic moment values of basic and amphoteric oxides is _______ 10−2BM (nearest integer). (Given atomic number of Cr is 24)

Q57.Consider the following first order gas phase reaction at constant temperature A(g) →2 B( g) + C(g) If the total pressure of the gases is found to be 200 torr after 23sec. and 300 torr upon the complete decomposition of A after a very long time, then the rate constant of the given reaction is ______ ×10−2 s−1 (nearest integer) [Given : log10(2) = 0.301]

Q57.Consider the following transformation involving first order elementary reaction in each step at constant Step 2 −temperature as shown below. A + B Step 1C → P Some details of the above reactions are listed below. Step 3 Step Rate constant (sec−1) Activation energy (kJ mol−1) 1 k1 300 If the overall rate constant of the above 2 k2 200 3 k3 Ea3 transformation (k) is given as k = k1k2 and the overall activation energy (Ea) is 400 kJ mol−1 , then the value k3 of Ea3 is kJmol−1 (nearest integer)

Q57.The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products A and B along with the evolution of CO2 . The sum of spin-only magnetic moment values of A and B is ______ B.M. (Nearest integer) [Given atomic number : C : 6, Na : 11, O : 8, Fe : 26, Cr : 24]

Q58.The number of halobenzenes from the following that can be prepared by Sandmeyer's reaction is _______

Q58. The total number of hydrogen atoms in product 𝐴 and product 𝐵 is__________.

Q58.Major product B of the following reaction has _______ π-bond.

Q58.The following data were obtained during the first order thermal decomposition of a gas A at constant volume: Ag →2 Bg + Cg S. No Time/s Total pressure/(atm) 1 . 0 0 . 1 2 . 115 0 . 28 The rate constant of the reaction is _______ × 10-2s-1 (nearest integer)

Q58.Phthalimide is made to undergo following sequence of reactions. Total number of π bonds present in product 'P' is/are ______

Q59.For a reaction taking place in three steps at same temperature, overall rate constant K = K1K2 . If Ea1, Ea2 and K3 Ea3 are 40, 50 and 60 kJ / mol respectively, the overall Ea is _________ kJ / mol .

Q59.The number of the correct reaction(s) among the following is ______

Q59.Number of metal ions characterized by flame test among the following is _________. Sr2 + , Ba2 + , Ca2 + , Cu2 + , Zn2 + , Co2 + , Fe2 +

Q59.A transition metal ' M ' among Sc, Ti, V, Cr, Mn and Fe has the highest second ionisation enthalpy. The spin- only magnetic moment value of M+ ion is _______. BM (Near integer) (Given atomic number Sc : 21, Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26)

Q60. Xg of ethanamine was subjected to reaction with NaNO2/HCl followed by hydrolysis to liberate N2 and HCl. The HCl generated was completely neutralised by 0.2 moles of NaOH. X is ______ g. ∈C : Im and S3 = {z ∈C : Re(z) ≥0}. Then the

Q60.The total number of carbon atoms present in tyrosine, an amino acid, is _______

Q60. The ratio of number of oxygen atoms to bromine atoms in the product Q is ______ ×10−1 .