In a zero-order reaction, if the initial concentration of the reactant is doubled, the time required for half the
reactant to be consumed
(A) increases two-fold (B) increases four-fold (C) decreases by half (D) does not change
The spin-only magnetic moments of [Mn(CN)6]4– and [MnBr4]2– in Bohr Magnetons, respectively, are
(A) 5.92 and 5.92 (B) 4.89 and 1.73 (C) 1.73 and 5.92 (D) 1.73 and 1.73
The standard Gibbs free energy change (ΔGº in kJ mol–1), in a Daniel cell ( Eº 1.1 V
cell = ), when 2 moles of
Zn(s) is oxidized at 298 K, is closest to
(A) – 212.3 (B) – 106.2 (C) – 424.6 (D) – 53.1
To obtain a diffraction peak, for a crystalline solid with interplane distance equal to the wavelength of
incident X-ray radiation, the angle of incidence should be
(A) 90º (B) 0º (C) 30º (D) 60º
When the size of a spherical nanoparticle decreases from 30 nm to 10nm, the ratio surface area/volume
becomes
(A) 1/3 of the original (B) 3 times the original
(C) 1/9 of the original (D) 9 times the original
For a process to occur spontaneously
(A) only the entropy of the system must increase
(B) only the entropy of the suroundings must increase
(C) either the entropy of the system or that of the surroundings must increase
(D) the total entropy of the system and the surroundings must increase
The rate of gas phase chemical reactions generally increases rapidly with rise in temperature. This is mainly
because
(A) the collision frequency increases with temperature
(B) the fraction of molecules having energy in excess of the activation energy increases with temperature
(C) the activation energy decreases with temperature
(D) the average kinetic energy of molecules increases with temperature
At 298 K, the ratio of osmotic pressures of two solutions of a substance with concentrations of 0.01 M and
0.001 M, respectively, is
(A) 1 (B) 100 (C) 10 (D) 1000
Assuming ideal behaviour, the enthalpy and volume of mixing of two liquids, respectively, are
(A) zero and zero (B) + ve and zero (C) –ve and zero (D) – ve and – ve