Practice Questions

Q51.The molarity of 1L orthophosphoric acid H3PO4 having 70% purity by weight (specific gravity 1 .54 g cm−3 ) is ______ M. (Molar mass of H3PO4 = 98 g mol-1) o

Q51.In an atom, total number of electrons having quantum numbers n = 4, | ml| = 1 and ms = −12 is ______

Q51.Number of moles of methane required to produce 22g CO2 ( g ) after combustion is x × 10 – 2 moles. The value of x is

Q51.Molarity (M) of an aqueous solution containing x g of anhyd. CuSO4 in 500 mL solution at 32∘C is 2 × 10−1M. Its molality will be ______ ×10−3 m . (nearest integer). [Given density of the solution = 1.25 g/mL]

Q51.Mass of methane required to produce 22 g of CO after complete combustion is g. (Given Molar mass in g mol- 1, C = 12. 0, H = 1. 0, O = 16. 0)

Q51.The de-Broglie's wavelength of an electron in the 4th orbit is πa0 ⋅(a0 = Bohr's radius ) JEE Main 2024 (04 Apr Shift 1) JEE Main Previous Year Paper

Q51.The maximum number of orbitals which can be identified with n = 4 and ml = 0 is ______ JEE Main 2024 (04 Apr Shift 2) JEE Main Previous Year Paper

Q51.Volume of 3M NaOH (formula weight 40 g mol-1 ) which can be prepared from 84 g of NaOH is ____ × 10-1dm3. Q52.9 . 3 g of aniline is subjected to reaction with excess of acetic anhydride to prepare acetanilide. The mass of acetanilide produced if the reaction is 100% completed is _____ × 10-1 g. (Given molar mass in g mol-1 N = 14, O = 16, C = 12, H = 1 ) Q53.1 mole of PbS is oxidised by X moles of O3 to get Y moles of O2 . X + Y =

Q51.Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter 10−15 m is ________. 109 ms−1 (nearest integer) [Given : mass of electron = 9.1 × 10−31 kg, Plank's constant (h) = 6.626 × 10−34Js] (Value of π = 3.14)

Q51.Consider the following reaction: 3PbCl2 + 2NH43PO4 →Pb3PO42 + 6NH4Cl If 72 mmol PbCl2 is mixed with 50 mmol of NH43PO4, then amount of Pb3PO42 formed in mmol. (nearest integer)

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.]

Q51. A hypothetical electromagnetic wave is show below. The frequency of the wave is x × 1019 Hz . x = ______ (nearest integer)

Q51.The total number of molccules with zero dipole moment among CH4, BF3, H2O, HF, NH3, CO2 and SO2 is ______.

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.Number of compounds with one lone pair of electrons on central atom amongst following is _ O3, H2O, SF4, ClF3, NH3, BrF5, XeF4

Q52.Number of molecules from the following which can exhibit hydrogen bonding is _______ (nearest integer) –5

Q52.For hydrogen atom, energy of an electron in first excited state is −3.4eV, K. E. of the same electron of hydrogen atom is xeV . Value of x is ______ ×10−1eV . (Nearest integer)

Q52.Total number of electrons present in (π∗) molecular orbitals of O2, O2+ and O−2 is _______.

Q52.Two reactions are given below: 3 ( s ) , 𝛥Ho = - 822 kJ / mol 2Fe ( s ) + 2O2 ( g ) →Fe2O3 1 C ( s ) + 2O2 ( g ) →CO ( g ) , 𝛥Ho = - 110 kJ / mol Then enthalpy change for following reaction 3C ( s ) + Fe2O3 ( s ) →2Fe ( s ) + 3CO ( g )

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

Q52.The total number of 'Sigma' and Pi bonds in 2-formylhex-4-enoic acid is

Q52.Number of molecules having bond order 2 from the following molecules is ________ C2, O2, Be2, Li2, Ne2, N2, He2 Q53. Δvap H⊖ for water is +40.79 kJ mol−1 at 1 bar and 100∘C. Change in internal energy for this vapourisation under same condition is kJmol−1 . (Integer answer) (Given R = 8.3JK−1 mol−1 ) JEE Main 2024 (08 Apr Shift 2) JEE Main Previous Year Paper

Q52.If IUPAC name of an element is "Unununnium" then the element belongs to nth group of periodic table. The value of n is _______.

Q52.The ionization energy of sodium in kJ mol – 1 . If electromagnetic radiation of wavelength 242 nm is just sufficient to ionize sodium atom is ______.(nearest integer)

Q52.The total number of species from the following in which one unpaired electron is present, is _______ N2, O2, C−2 , O−2 , O2−2 , H+2 , CN−, He+2