Chemistry Question Bank

The rate of a first-order reaction is 0.04 mol L s at 10 seconds and 0.03 mol L s at 20 seconds after initiation of the reaction. The half-life period of the reaction is. (NEET 2016)

A first order reaction is 50% completed in 1.26 10 x s. How much time would it take for 100% completion? (JIPMER 2017) (a) 1.26 10 s x (b) 2.52 10 s x (c) 2.52 10 s x

A first order reaction has a specific reaction rate of 10– 2 sec–1. How much time will it take for 20g of the reactant to reduce to 5 g? (NEET 2017)

Mechanism of a hypothetical reaction X Y XY -> is given below: (i) fast X X X (ii) slow -> X Y XY Y (iii) fast X Y XY -> The overall order of the reaction will be; (NEET 2017)

When initial concentration of the reactant is doubled, the half-life period of a zero order reaction (NEET 2018)

The correct difference between first and second order reactions is that (NEET 2018)

Find out time period of Ist order reaction when reaction complete 2/3rd, if the value of rate constant is 4.3 10 s x (JIPMER 2019) (a) 0.0025 10 sec x (b) 0.25 10 sec x (c) 0.025 10 sec x (d) 2.5 10 sec x

If half-life of a substance is 36 minutes. Find amount left after 2 hrs. Initial amount is 10 g. (JIPMER 2019)

Formula for half-life of a zero order reaction is (JIPMER 2019) (a) C k (b) C 2k (c) 2C k (d) 2C 2k

For a reaction, activation energy Ea = 0 and the rate constant at 200 K is 1.6 × 106 s–1. The rate constant at 400 K will be: [Given that gas constant R=8.314 J K–1 mol–1] (Odisha NEET 2019)

A first order reaction has a rate constant of 2.303 × 10– 3 s–1. The time required for 40 g of this reactant to reduce to 10 g will be: [Given that log10 2 = 0.3010 (Odisha NEET 2019)

For the chemical reaction: (NEET 2019) N g H g NH g The correct option is: (a) d N d NH dt dt (b) d N d NH dt dt (c) d H d NH dt dt (d) d H d NH dt dt

If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by: (NEET 2019)

The half-life for a zero order reaction having 0.02 M intial concetration of reactant is 100 s. The rate constant (in mol L-1 s-1) for the reaction (NEET 2020) (a) 1.0 10 x (b) 2.0 10 x (c) 2.0 10 x (d) 1.0 10 x

The rate constant for a first order reaction is 4.606 10 s x . The time required to reduce 2.0 g of the reactant to 0.2 g is: (NEET 2020)

An increase in the concentration of the reactants of a reaction leads to change in: (NEET 2020)

The slope of Arrhenius plot (ln k v/s 1/T) of first order reaction is 5 10 . K x The value of a E of the reaction is. Choose the correct option for your answer. (Given R = 8.314 Jk-1 mol-1) (NEET 2021)

For a reaction A → B, enthalpy of reaction is -4.2 kJ mol-1 and enthalpy of activation is 9.6 kJ mol-1. The correct potential energy profile for the reaction is shown in option. (NEET 2021) (a) (b) (c) (d)

The correct expression for the rate constant for reactions of zero-order is

If ‘a’ is the initial concentration of the reactant, the time taken for completion of the reaction, if it is of zero-order, will be

For a general reaction X -> Y, the plot of conc. of X vs time is given in the figure. What is the order of the reaction and what are the units of rate constant?

The rate constant of a first order reaction is 15 ×10-3 s–1. How long will 5.0 g of this reactant take to reduce to 3.0 g?

1.386 hours are required for the disappearance of 75% of a reactant of first-order reaction. What is the rate constant of the reaction?

For the first order reaction A ⟶ Products, which one of the following is the correct plot of log [A] versus time? (a) (b) (c) (d)

The rate constant for a zero order reaction is 2 × 10–2 mol L–1 sec–1. If the concentration of the reactant after 25 sec is 0.5 M, the initial concentration must have been