Q. Among the following compounds, a normal spinel is (A) MgFe2O4 (B) ZnFe2O4 (C) CoFe2O4 (D) CuFe2O4 Ans: ZnFe2O4 Solution: A spinel compound is made up of eight FCC unit cells with a 2x2x2 oxygen ion configuration. According to the spaces occupied by the cations in the structure, they can be classified into two types- […]
Among the following compounds, a normal spinel is Read More »
Q. The experimentally observed magnetic moment values, which match well with the spin-only values for the pair of aqueous ions is (Atomic number: Cr = 24, Co = 27, Gd = 64, Tb = 65, Dy = 66 and Lu = 71) (A) Cr(III) and Gd(III) (B) Co(II) and Gd (III) (C) Cr(III) and Dy(III)
Q. Gas phase bond length and dipole moment of a compound (MX) is 3 Å and 10.8 D, respectively. The ionic character in gas phase MX is _________________%. (Round off to one decimal place) (1D = 3.336 × 10–30 C m) Solution: To determine the Ionic character of a given compound, Dipole moment is necessary to
Q. In a 400 MHz 1H NMR spectrometer, a proton resonates at 1560 Hz higher than that of tetramethylsilane. The chemical shift value of this proton is___________ppm. (Round off to one decimal place) (Chemical shift of tetramethylsilane is fixed at zero ppm) Solution: The chemical shift of Nuclear Magnetic Resonance Spectroscopy is the relative resonant
Q. Consider a system of three identical and distinguishable non-interacting particles and three available nondegenerate single particle energy levels having energies 0, e and 2e. The system is in contact with a heat bath of temperature T K. A total energy of 2ɛ is shared by these three particles. The number of ways the particles
Q. Consider a two-state system at thermal equilibrium having energies 0 and 2kBT for which the degeneracies are 1 and 2, respectively. The value of the partition function at the same absolute temperature T is ______. (Round off to two decimal places) (kB is the Boltzmann constant) Solution: General formula is q = Ʃ gi e-Ei / KT, For
Q. The entropy change for the melting of ‘x’ moles of ice (heat of fusion is 80 cal g–1) at 273 K and 1 atm pressure is 28.80 cal K–1. The value of ‘x’ is___________. (Round off to two decimal places) (Molecular weight of water =18 g/mol) Solution: Δ S = Δ H/ T , OR Δ
Q. An ideal gas occupies an unknown volume V liters (L) at a pressure of 12 atm. The gas is expanded isothermally against a constant external pressure of 2 atm so that its final volume becomes 3 L. The work involved for this expansion process is______cal. (Round off to two decimal places) (Gas constant R
Q. On heating a sample of 25 mg hydrated compound (molecular weight = 250 g/mol) in thermogravimetric analysis, 16 mg of dehydrated compound remains. The number of water molecules lost per molecule of hydrated compound is . (Molecular weight of water = 18 g/mol) Solution: 25 mg Compound contains (25-16) g of Water = 9
Q. The number of 1H NMR signals observed for the following compound is Ans: The number of 1H NMR signals observed for the following compound is 6 Solution: Enantiotropic protons are protons that are replaced by another group of protons. They have the same mirror image and chemical shift in the NMR spectrum. Therefore, Here
The number of 1H NMR signals observed for the following compound is Read More »
