167 questions from a source that prints this span of years rather than the year of each question. Each opens with its answer and explanation.
ABC26PH0631 · For an electron whose x-positional uncertainity is 1 × 10-10 m, the uncertainity in x-component of the velocity in ms-1 will be of the… · Atomic Structure – General
ABC26PH0632 · Identify the correct statement regarding Einstein's photoelectic effect · Atomic Structure – General
ABC26PH0633 · Ionisation energy of hydrogen atom is ground state is 13.6 eV. The energy released (in eV) for third member of Balmer series is · Atomic Structure – General
ABC26PH0636 · Given that the radius of the first Bohr orbit of hydrogen atom is 53 pm, the radius of its third Bohr orbit is ____ pm. (Round off to the… · Atomic Structure – General
ABC26PH0638 · Two sets of quantum numbers with the same number of radial nodes are · Atomic Structure – General
ABC26PH0639 · The ratio of the 2p → 1s transition energy in He^+ to that in the H atom is closest to · Atomic Structure – General
ABC26PH0641 · The temperature (T) dependence of the equilibrium constant (K) of a chemical reaction is correctly described by the following statement: · Chemical Equilibrium – General
ABC26PH0642 · The reaction N2 + 3H2 ⇌ 2NH3 is carried out at 300 K by mixing N2 and H2. The standard free energy of formation of NH3 is -16.4 kJ/mol… · Chemical Equilibrium – General
ABC26PH0649 · A vessel contains a mixture of H2 and N2 gas. The density of this gas mixture is 0.2 g L-1 at 300 K and 1 atm. Assuming that both the gases… · Chemical Equilibrium – General
ABC26PH0650 · Consider the reaction CO(g) + 1/2O2(g) → CO2(g). The value of Delta U for the reaction at 300 K is -281.8 kJ mol-1. The value of Delta H at… · Chemical Equilibrium – General
ABC26PH0653 · For the reaction, Q + R k-1k1⇌ X k2 P k1 = 2.5 × 105 L mol-1 s-1, k-1 = 1.0 × 104 s-1 and k2 = 10 s-1. Under steady state approximation… · Chemical Kinetics – General
ABC26PH0654 · The intensity of a monochromatic visible light is reduced by 90% due to absorption on passing through a 5.0 mM solution of a compound. If… · Chemical Kinetics – General
ABC26PH0655 · Elemental analysis of an organic compound contaming C, H and O gives percentage composition: C : 39.9% and H : 6.7%. If the molecular… · Chemical Kinetics – General
ABC26PH0657 · The half-life of the chemical reaction, A → Product, for initial reactant concentrations of 0.1 and 0.4 mol L-1 are 200 and 50 s… · Rate Laws Order
ABC26PH0662 · An aqueous solution containing 1 g L-1 of a polymer exerts osmotic pressure of 4 torr at 300 K. Given R=0.082 L atm, the molar mass (g… · Chemical Kinetics – General
ABC26PH0663 · The most viscous liquid is · Rate Laws Order
ABC26PH0664 · Addition of 1.0 g of a compound to 10 g of water increases the boiling point by 0.3° C. The amount of compound needed to prepare a 500 ml… · Chemical Kinetics – General
ABC26PH0665 · The kinetics of the reaction 2 N2 O5 → 4 NO2+O2 in liquid bromine medium was measured independently for three different initial… · Rate Laws Order
ABC26PH0666 · A 2.5 × 10-4 M solution of a complex exhibits an absorption maximum at 625 nm with an absorbance of 0.90 when measured in a cuvette with a… · Chemical Kinetics – General
ABC26PH0667 · For a reaction, the rate constant at 25°C is doubled when the temperature is raised to 45°C. The activation energy (in kJ mol-1) of the… · Arrhenius Activation
ABC26PH0668 · An aqueous solution of hemoglobin has a molar absorptivity value of 18,600 L mol-1 cm-1 for an absorbance value of 0.1 at 540 nm (Given… · Chemical Kinetics – General
ABC26PH0670 · For a particular reaction at constant temperature, a plot of inverse of reactant concentration (1/([A])) versus time is a straight line… · Chemical Kinetics – General
ABC26PH0672 · The half-life of any zero-order reaction is: · Rate Laws Order
ABC26PH0673 · The percent transmittance of a solution having absorbance (optical density) 1.0 is · Chemical Kinetics – General
ABC26PH0677 · For the formation of B from A, heat liberated is 20 kJ mol-1. If the activation energy for the reaction B → A is 100 kJ mol-1, then the… · Arrhenius Activation
ABC26PH0678 · For the reaction A + B → Z, the concentration of Z at time t is given by [Z] = [A]t=0(1 - e-kt) + [Z]t=0, where k is the rate constant. The… · Rate Laws Order
ABC26PH0680 · For a zero order reaction, units of the rate constant is expressed as · Rate Laws Order
ABC26PH0681 · 1 × 10-6 moles of the enzyme carbonic anhyrase dehydrates H2 CO3 to produce 0.6 mol of CO2 per second. The turnover number of the enzyme is: · Enzyme Kinetics
ABC26PH0682 · The rate of a chemical reaction doubles when the temperature is changed from 300 K to 310 K. Calculate activation energy in kJ mol-1 · Arrhenius Activation
ABC26PH0683 · For a reaction with rate equation -dC/dt = kC2, C0 and C are the concentrations of the reactant at time 0 and t respectively. If 10 minutes… · Chemical Kinetics – General
ABC26PH0684 · An enzyme following Michaelis-Menten kinetics was found to have highest activity at 37°C and pH 7.0. If the maximum velocity Vmax for this… · Enzyme Kinetics
ABC26PH0686 · From the reaction aA → products, the plot of 1/([A]) versus time (t) gives a straight line. Order of the reaction is · Chemical Kinetics – General
ABC26PH0688 · Given that Eo_Fe2+/Fe = -0.44 V and Eo_Fe3+/Fe2+ = 0.77 V, the Eo_Fe3+/Fe is : · Electrochemistry – General
ABC26PH0689 · The statement that is correct for both electrochemical (galvanic) cells and electrolytic cell is : · Nernst Cells
ABC26PH0690 · The standard potential of a Daniel cell is +1.10 V and the equilibrium constant for the cell reaction is 1.5 × 1037. It can be concluded… · Nernst Cells
ABC26PH0691 · Consider the following redox system. Q + 2H^+ + 2e^- ⇌ QH2 E° = 0.699 V Calculate the pH of the solution at 298 K, if the redox potential… · Electrochemistry – General
ABC26PH0694 · The molality of (NH4)2SO4 solution that has the same ionic strength as 1 mol kg-1 solution of KCl is · Debye Huckel
ABC26PH0695 · A concentration cell with two hydrogen electrodes at two different pressures is depicted as H2(g)(Pt) (pH2 = p1) | HCl(aq) | H2(g)(Pt) (pH2… · Electrochemistry – General
ABC26PH0696 · MnO4^-(aq) + Zn(s) + H3O^+(aq) → Mn2+(aq) + Zn2+(aq) + H2O(l) For the above reaction if the equilibrium constant at 298 K is represented by… · Electrochemistry – General
ABC26PH0697 · The concentration of K^+ ion inside a biological cell is 20 times higher than outside. The magnitude of potential difference between the… · Electrochemistry – General
ABC26PH0698 · The standard reduction potentials of the Fe3+/Fe2+ and Fe2+/Fe couples are 0.77 and -0.44 V, respectively. The standard reduction potential… · Electrochemistry – General
ABC26PH0699 · An electrochemical cell consists of two half-cell reactions AgCl(s) + e^- → Ag(s) + Cl^-(aq); Cu(s) → Cu2+(aq) + 2e^- The mass of copper… · Nernst Cells
ABC26PH0700 · For a cell reaction, Pb(s) + Hg2Cl2(s) → PbCl2(s) + 2Hg(l), ((∂ Eo)/(∂ T))P is 1.45 × 10-4 V K-1. The entropy change (in J mol-1 K-1) for… · Nernst Cells
ABC26PH0701 · The standard reduction potentials of Ce4+/Ce3+ and Fe3+/Fe2+ are 1.44 and 0.77 V, respectively. The log 10 K (K is the equilibrium… · Electrochemistry – General
ABC26PH0703 · The limiting molar conductivity of La3+ and Cl^- ions in aqueous medium at 298 K are 209.10 × 10-4 and 76.35 × 10-4 S m2 mol-1… · Conductance
ABC26PH0704 · The mean ionic activity coefficient for a 0.01 M aqueous solution of Ca3(PO4)2 is ____ (Round off to three decimal places) (Given : log 10… · Electrochemistry – General
ABC26PH0705 · For the reaction, CuSO4(aq) + Zn(s) → ZnSO4(aq) + Cu(s), the value of Delta G° (in kJ mol-1) is ____ (Round off to the nearest integer)… · Electrochemistry – General
ABC26PH0706 · The mean ionic activity coefficient of 0.004 molal CaCl2 in water at 298 K (rounded off to thre decimal places) is ________. (Given… · Debye Huckel
ABC26PH0707 · For the distribution of molecular velocities of gases, identify the correct order from following (where vmp, vav, vrms are the most… · Gaseous State – General
ABC26PH0708 · The molar heat capacity at constant volume of a colourless gas is found to be 25 J mol-1 K-1 at room temperature. The gas must be · Gaseous State – General