Practice Questions

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.A diatomic molecule has a dipole moment of 1 .2 D. If the bond distance is 1 A, then fractional charge on each atom is _____ × 10−1 esu. (Given 1D = 10−18 esu cm) JEE Main 2024 (31 Jan Shift 2) JEE Main Previous Year Paper

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.Number of compounds from the following with zero dipole moment is ______ HF, H2, H2 S, CO2, NH3, BF3, CH4, CHCl3, SiF4, H2O, BeF2

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.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 value of Rydberg constant (RH) is 2.18 × 10−18 J. The velocity of electron having mass 9.1 × 10−31 kg in Bohr's first orbit of hydrogen atom = _______ ×105 ms−1 (nearest integer).

Q52.For a certain reaction at 300 K, K = 10, then ΔG° for the same reaction is – ________ × 10-1 kJ mol-1 . (Given R = 8 . 314JK-1 mol-1)

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

Q52.Number of molecules/species from the following having one unpaired electron is O2, O−12 , NO, CN−1, O2−2

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

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

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

Q52.Number of compounds / species from the following with non-zero dipole moment is ______ BeCl2, BCl3, NF3, XeF4, CCl4, H2O, H2 S, HBr, CO2, H2, HCl

Q52.Lowest Oxidation number of an atom in a compound A2B is -2 . The number of an electron in its valence shell is

Q52.The number of electrons present in all the completely filled subshells having n = 4 and s = + 12 is ____ (Where n = principal quantum number and s = spin quantum number)

Q53.Combustion of 1 mole of benzene is expressed at C6H6(l) + 152 O2( g) →6CO2( g) + 3H2O(l). The standard enthalpy of combustion of 2 mol of benzene is −′x′kJ. x = ______ Given: 1. standard Enthalpy of formation of 1 mol of C6H6(l), for the reaction 6C (graphite) +3H2( g) →C6H6(l) is 48.5 kJ mol−1 . 2. Standard Enthalpy of formation of 1 mol of CO2( g), for the reaction C (graphite) +O2( g) →CO2( g) is −393.5 kJ mol−1 . 3. Standard and Enthalpy of formation of 1 mol of H2O(l), for the reaction H2( g) + 12 O2( g) →H2O(l) is −286 kJ mol−1 .

Q53.The pH of an aqueous solution containing 1M benzoic acid pKa = 4 . 20 and 1M sodium benzoate is 4 . 5 . The volume of benzoic acid solution in 300 mL of this buffer solution is __________mL.

Q53.The number of species from the following in which the central atom uses sp3 hybrid orbitals in its bonding is _________. NH3, SO2, SiO2, BeCl2, CO2, H2O, CH4, BF3

Q53.If 5 moles of an ideal gas expands from 10L to a volume of 100L at 300K under isothermal and reversible condition then work, w, is −x J. The value of x is - _______. (Given R = 8 .314 J K-1 mol-1)

Q53.Sum of bond order of CO and NO+ is

Q53. Consider the figure provided. 1 mol of an ideal gas is kept in a cylinder, fitted with a piston, at the position A, at 18∘C . If the piston is moved to position B , keeping the temperature unchanged, then ' x ' L atm work is done in this reversible process. x = ______ L atm. (nearest integer) [Given : Absolute temperature = ∘C + 273.15, R = 0.08206 L atm mol−1 K−1 ]

Q53.Three moles of an ideal gas are compressed isothermally from 60 L to 20 L using constant pressure of 5 atm . Heat exchange Q for the compression is - ______ Lit. atm.

Q53.The enthalpy of formation of ethane (C2H6) from ethylene by addition of hydrogen where the bond-energies of C −H, C −C, C = C, H −H are 414 kJ, 347 kJ, 615 kJ and 435 kJ respectively is kJ

Q53.The number of molecules/ion/s having trigonal bipyramidal shape is …….. . PF5, BrF5, PCl5, PtCl4 2 - , BF3, Fe(CO ) 5