Practice Questions
1,068 questions across 23 years of JEE Main — find and practise any topic!
Found 1,068 results
Q32.The number of given orbitals which have electron density along the axis is px, py, pz, dxy, dyz, dxz, d2z, dx2−y2
Q32.The number of following statement/s which is/are incorrect is ______ A) Line emission spectra are used to study the electronic structure B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet. C) An absorption spectrum is like the photographic negative of an emission spectrum D) The element helium was discovered in the sun by spectroscopic method
Q32.The total number of lone pairs of electrons on oxygen atoms of ozone is
Q32.The volume of hydrogen liberated at STP by treating 2. 4 g of magnesium with excess of hydrochloric acid is ...... ×10−2 L. Given Molar volume of gas is 22. 4 L at STP. Molar mass of magnesium is 24 g mol−1
Q33.The number of molecules or ions from the following, which do not have odd number of electrons are _____ . (A) NO2 (B) ICl−4 (C) BrF3 (D) ClO2 (E) NO+2 (F) NO
Q33.The number of atomic orbitals from the following having 5 radial nodes is 7s, 7p, 6s, 8p, 8d
Q33.Sum of π-bonds present in peroxodisulphuric acid and pyrosulphuric acid is
Q33.Values of work function (W0) for a few metals are given below Metal Li Na K Mg Cu Ag W0 eV 2. 42 2. 3 2. 25 3. 7 4. 8 4. 3 The number of metals which will show photoelectric effect when light of wavelength 400 nm falls on it is _____ Given: h = 6. 6 × 10–34 J s c = 3 × 108 ms–1 e = 1. 6 × 10–19 C
Q33.A litre of buffer solution contains 0. 1 mole of each of NH3 and NH4 Cl. On the addition of 0. 02 mole of HCl by dissolving gaseous HCl , the pH of the solution is found to be _____ × 10−3 (Nearest integer) Given: pKb(NH3) = 4. 745 log 2 = 0. 301 log 3 = 0. 477 T = 298 K]
Q33.The number of correct statements from the following is ........... A. For 1s orbital, the probability density is maximum at the nucleus B. For 2s orbital, the probability density first increases to maximum and then decreases sharply to zero. C. Boundary surface diagrams of the orbitals encloses a region of 100% probability of finding the electron. D. p and d -orbitals have 1 and 2 angular nodes respectively E. probability density of p -orbital is zero at the nucleus
Q34.The number of species trom the following carrying a single lone pair on central atom Xenon is XeF+5 , XeO3, XeO2 F2, XeF−5 , XeO3 F2, XeOF4, XeF4
Q34.The density of a monobasic strong acid (Molar mass 24. 2 g mol) is 1. 21 kg L . The volume of its solution required for the complete neutralization of 25 mL of 0. 24 M NaOH is 10−2 mL (Nearest integer) Q35.' 25 volume' hydrogen peroxide means (1) 1 L marketed solution contains 250 g of H2O2 . (2) 1 L marketed solution contains 75 g of H2O2 . (3) 100 mL marketed solution contains 25 g of (4) 1 L marketed solution contains 25 g of H2O2 . H2O2 .
Q34.The number of species having a square planar shape from the following is XeF4, SF4, SiF4, BF4−, BrF4−, [Cu (NH3)4]2+, [FeCl4]2−, [PtCl4]2−
Q35.Amongst the following, the number of species having the linear shape is XeF2, I+3 , C3O2, I−3 , CO2, SO2, BeCl2 and BCl⊖2
Q35.Consider the following reaction approaching equilibrium at 27°C and 1 atm pressure Kt=03 A + B ⇌ C + D Kr=102 The standard Gibb's energy change (ΔrG°) at 27°C is (−) _____ kJmol−1 (Nearest integer). (Given : R = 8. 3J K−1 mol−1 and ln 10 = 2. 3 )
Q35.The maximum number of lone pairs of electron on the central atom from the following species is ...... ClO3−, XeF4, SF4 and l3−
Q35.When the hydrogen ion concentration [H+]changes by a factor of 1000 , the value of pH of the solution (1) increases by 1000 units (2) decreases by 3 units (3) decreases by 2 units (4) increases by 2 units
Q35.One mole of an ideal monoatomic gas is subjected to changes as shown in the graph. The magnitude of the work done (by the system or on the system) is _______ J (nearest integer) Given : log 2 = 0.3, ln 10 = 2.3
Q35.Consider the following equation: 2 SO2(g) + O2(g) ⇌2 SO3(g), ΔH = −190 kJ. The number of factors which will increase the yield of SO3 at equilibrium from the following is _____ . A. Increasing temperature B. Increasing pressure C. Adding more SO2 D. Adding more O2 E. Addition of catalyst
Q35.The effect of addition of helium gas to the following reaction in equilibrium state at constant volume, is : PCI5( g) ⇌PCl3( g) + Cl2( g) JEE Main 2023 (01 Feb Shift 2) JEE Main Previous Year Paper (1) the equilibrium will shift in the forward direction (2) the equilibrium will go backward due to and more of Cl2 and PCl3 gases will be suppression of dissociation of PCl5 . produced. (3) helium will deactivate PCl5 and reaction will (4) addition of helium will not affect the equilibrium. stop.
Q35.At 298 K N2(g) + 3H2(g) ⇌2 NH3(g), K1 = 4 × 105 N2(g) + O2(g) ⇌2 NO(g), K2 = 1. 6 × 1012 H2(g) + 12 O2(g) ⇌H2O(g), K3 = 1. 0 × 10−13 Based on above equilibria, the equilibrium constant of the reaction, 2 NH3(g) + 25 O2( g) ⇌2 NO(g) + 3H2O(g) is _____ ×10−33 (Nearest integer)
Q35.In an ice crystal, each water molecule is hydrogen bonded to _____ neighbouring molecules.
Q35.The number of following factors which affect the percent covalent character of the ionic bond is______ A) Polarising power of cation B) Extent of distortion of anion C) Polarisability of the anion D) Polarising power of anion
Q36.The total number of intensive properties from the following is........... Volume, Molar heat capacity, molarity, Eocell ,Gibbs free energy change, Molar mass, Mole Q37. 4. 5 moles each of hydrogen and iodine is heated in a sealed ten litre vessel.At equilibrium, 3 moles of HI were found. The equilibrium constant for H2(g) + I2(g) ⇌2 HI(g) is ........
Q36.The strength of 50 volume solution of hydrogen peroxide is _____ g/L (Nearest integer). Given: Molar mass of H2O2 is 34 g mol−1 Molar volume of gas at STP = 22. 7 L.