Practice Questions

Q51.When 35 mL of 0. 15 M lead nitrate solution is mixed with 20 mL of 0. 12 M chromic sulphate solution, ____________ ×10−5 moles of lead sulphate precipitate out. (Round off to the Nearest Integer).

Q51. Consider the above reaction. The percentage yield of amide product is (Round off to the Nearest Integer). (Given : Atomic mass : C : 12. 0u, H : 1. 0u N : 14. 0u, O : 16. 0u, Cl : 35. 5u)

Q51.An aqueous KCl solution of density 1. 20 g mL−1 has a molality of 3. 30 mol kg−1 . The molarity of the solution in molL−1 is____.(The Nearest integer) [ Molar mass of KCl = 74. 5 g]

Q51.Electromagnetic radiation of wavelength 663 nm is just sufficient to ionise the atom of metal A . The ionization energy of metal A in kJ mol−1 is ___. (Rounded-off to the nearest integer) [h = 6. 63 × 10−34 Js, c = 3. 00 × 108 ms−1, NA = 6. 02 × 1023 mol−1]

Q51.The density of NaOH solution is 1. 2 g cm−3. The molality of this solution is m (Round off to the Nearest Integer): [Use : Atomic masses : Na : 23. 0u O : 16. 0u H : 1. 0u Density of H2O : 1. 0 g cm−3]

Q51.The wavelength of electrons accelerated from rest through a potential difference of 40 kV is X × 10−12 m. The value of x is. (Nearest integer) Given: Mass of electron = 9. 1 × 10−31 kg Charge on an electron = 1. 6 × 10−19C Planck's constant = 6. 63 × 10−34 Js

Q51.The number of significant figures in 0. 00340 is _________

Q51.The reaction that occurs in a breath analyser, a device used to determine the alcohol level in a person's blood stream is 2 K2 Cr2 O7 + 8H2 SO4 + 3C2H6O →2 Cr2 (SO4)3 + 3C2H4O2 + 2 K2 SO4 + 11H2O If the rate of appearance of Cr2 (SO4)3 is 2. 67 mol min−1 at a particular time, the rate of disappearance of C2H6O at the same time is mol min−1. (Nearest integer) Q52. 1 kg of 0. 75 molal aqueous solution of sucrose can be cooled up to −4°C before freezing. The amount of ice (in g ) that will be separated out is ___________. (Nearest integer) [Given : Kf(H2O) = 1. 86 K kg mol−1 ]

Q51.The value of magnetic quantum number of the outermost electron of Zn+ ion is _________ . (Integer answer) JEE Main 2021 (31 Aug Shift 2) JEE Main Previous Year Paper

Q51.The number of significant figures in 50000. 020 × 10−3 is

Q51.Methylation of 10 g of benzene gave 9. 2 g of toluene. Calculate the percentage yield of toluene (Nearest integer)

Q51. Ge (Z = 32) in its ground state electronic configuration has x completely filled orbitals with ml = 0. The value of x is __________ .

Q51.A car tyre is filled with nitrogen gas at 35 psi at 27 °C . It will burst if pressure exceeds 40 psi. The temperature in ∘C at which the car tyre will burst is (Rounded-off to the nearest integer)

Q52.The number of lone pairs of electrons on the central I atom in I−3 is JEE Main 2021 (20 Jul Shift 1) JEE Main Previous Year Paper

Q52.A certain gas obeys P(Vm −b) = RT. The value of ( ∂P∂Z )T is RTxb . The value of x is (Integer answer) ( Z : compressibility factor)

Q52.A source of monochromatic radiation wavelength 400 nm provides 1000 J of energy in 10 seconds. When this radiation falls on the surface of sodium, x × 1020 electrons are ejected per second. Assume that wavelength 400 nm is sufficient for ejection of electron from the surface of sodium metal. The value of x is ______. (Nearest integer) h = 6 . 626 × 10-34 Js

Q52. AB3 is an interhalogen T-shaped molecule. The number of lone pairs of electrons on A is (Integer answer)

Q52.In gaseous triethyl amine the ′′−C −N −C −′′ bond angle is ____ degree.

Q52.According to the following figure, the magnitude of the enthalpy change of the reaction A + B →M + N in kJ mol−1 is equal to __________ . (Integer answer)

Q52.A proton and a Li3 + nucleus are accelerated by the same potential. If 𝜆Li and 𝜆p denote the de Broglie + 𝜆Li wavelengths of Li3 and proton respectively, then the value of is 𝑥× 10-1. The value of x 𝜆p is _____ (Rounded off to the nearest integer) [Mass of Li3 + = 8 . 3 mass of proton]

Q52.Five moles of an ideal gas at 293 K is expanded isothermally from an initial pressure of 2. 1 MPa to 1. 3 MPa against at constant external pressure 4. 3 MPa. The heat transferred in this process is ___ kJmol−1 . (Rounded-off to the nearest integer) [ Use R = 8. 314 J mol−1 K−1 ]

Q52.The total number of electrons in all bonding molecular orbitals of O2−2 is ......... (Round off to the nearest integer)

Q52.An accelerated electron has a speed of 5 × 106 ms−1 with an uncertainty of 0. 02%. The uncertainty in finding its location while in motion is x × 10−9 m. The value of x is __________. (Nearest integer) [Use mass of electron = 9. 1 × 10−31 kg, h = 6. 63 × 10−34 Js, π = 3. 14]

Q52.For water Δvap H = 41 kJ mol−1 at 373 K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is (kJmol−1) : [ Use : R = 8. 3 J mol−1 K−1]

Q52.The number of photons emitted by a monochromatic (single frequency) infrared range finder of power 1 mW and wavelength of 1000 nm, in 0. 1 second is x × 1013 . The value of x is (Nearest integer) (h = 6. 63 × 10−34 Js, c = 3. 00 × 108 ms−1):