Chemistry Question Bank

Half-lives of a first order and a zero order reaction are same. Then the ratio of the initial rates of first order reaction to that of the zero order reaction is (a) 0.693

Hydrolysis of methyl acetate in aqueous solution has been studied by titrating the liberated acetic acid against sodium hydroxide. The concentration of the ester at different times is given below. t/min C/mol L-1 0.85…

The following data were obtained during the first order thermal decomposition of SO2Cl2 at a constant volume. 2(g) 2(g) 2(g) SO Cl SO Cl -> Experimen t Time/s-1 Total pressure/atm 0.5 0.6 What is the rate of reaction…

1 mL of ethyl acetate was added to a flask containing 20 mL of N/20 HCl maintained at 25oC. 2 mL of the reaction mixture were withdrawn at different intervals and titrated with a standard alkali solution. The followin…

From the following data find rate constant of decomposition of H2O2 in aqueous solution Time (in minutes) Volume (in cc of KMnO4) 22.8 13.3 8.25

For the reaction : sunlight H Cl 2HCl ->

The initial rates of reaction 3A + 2B + C -> Products, at different initial concentrations are given below: Initial rate M s–1 [A]0 , M [B]0 , M [C]0 , M 5.0 × 10–3 0.010 0.005 0.010 5.0 × 10–3 0.010 0.005 0.015 1.0 ×…

The hypothetical reaction A B 2AB; -> follows the following mechanism Fast A A A, -> Slow Fast A B AB B,A B AB. -> -> The order of the overall reaction is

The reaction of hydrogen and iodine monochloride is given as: H g 2ICl g 2HCl g I g -> The reaction is of first order with respect to H2 (g) and ICl(g), following mechanisms were proposed. Mechanism A: H g 2…

For a certain reaction A -> products, the t1/2 as a function of [A]0 is given as below: [A]0 (M) : 0.1 0.025 t1/2 (min) : 100 Which of the following is/are true ?

In most cases, for a rise of 10K temperature the rate constant is doubled to tripled. This is due to the reason that (a)collision frequency increases by a factor of 2 to 3. (b)fraction of molecules possessing threshol…

The first order rate constant for a certain reaction increases from 1.667 × 10–6 s–1 at 727ºC to1.667 × 10–4 s–1 at 1571ºC. The rate constant at 1150ºC, assuming constancy of activation energy over the given temperatu…

Ea and H values of reactions R1, R2, R3 and R4 carried out at the same temperature are as given below: R1 Ea = 40 kJ mol–1, H = – 80 kJ mol–1 R2 Ea = 20 kJ mol–1, H = – 30 kJ mol–1 R3 Ea = 60 kJ mol–1, H = + 40 kJ mol…

The potential energy diagram for a reaction R P -> is given below o H of the reaction corresponds to the energy:

An endothermic reaction with high activation energy for the forward reaction is given by the diagram : (a) (b) (c) E E (d)

For a first order reaction A P, the temperature (T) dependent rate constant (k) was found to follow the equation 1 logk 6.0 T . The pre- exponential factor A and the activation energy Ea, respectively are: (a) 1.0…

Collision theory is used to explain how chemical species undergo a reaction. Using this theory and the kinetic molecular model, which of the following does NOT influence the rate of a chemical reaction?

Choose the correct answer out of the following choices. Assertion (A): Most people think diamond is forever. Reason (R): Conversion rate of diamond to graphite is very low.

Assertion (A): In rate law, unlike in the expression for equilibrium constants, the exponents for concentrations do not necessarily match the stoichiometric coefficients. Reason (R): It is the mechanism and not the ba…

Assertion (A): The order of a reaction can have fractional value. Reason (R): The order of a reaction cannot be written from balanced equation of a reaction.

Assertion (A): If the activation energy of a reaction is zero, temperature will have no effect on the rate constant. Reason (R): Lower the activation energy, faster is the reaction.

The instantaneous rate of reaction at the beginning of the reaction is

For the chemical equilibrium, CaCO (s) CaO(s) CO (g) , Hº can be determined from which one of the following graphs ? (a) (b) (c) (d)

Given : Reaction Equilibrium constant N2(g) + 3H2(g) 2NH3(g) K1 N2(g) + O2(g) 2NO(g) K2 H (g) O (g) H O(g) K3 The equilibrium constant K4 for the following reaction 2NH (g) O (g) 2NO(g) 3H …

N2(g) + 3H2(g) 2NH3(g) Initially the molar ratio of N2 and H2 was 1 : 3. At equilibrium, 50% of each has reacted. If the equilibrium pressure is P, the partial pressure of NH3 at equilibrium is: