Chemistry Question Bank

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 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)

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

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

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

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

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

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)

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)

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

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)

The addition of a catalyst during a chemical reaction alters which of the following quantities? (NEET 2016)

The decomposition of phosphine (PH3) on tungsten at low pressure is a first-order reaction. It is because the: (NEET II 2016)

The rate constant of the reaction A ->B is 0.6 × 10–3 mol L-1 second-1. If the concentration of A is 5 M then concentration of B after 20 minutes is: (NEET 2015 RS)

When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is: (NEET 2015)

The activation energy of a reaction can be determined from the slope of which of the following graphs? (NEET 2015)

The inversion of cane sugar is first order in [sugar] and proceeds with half-life of 600 minutes at pH = 4 for a given concentration of sugar. However, if pH = 5, the half-life changes to 60 minutes. The rate law expr…

A reaction is 50% completed in 2 hours and 75% completed in 4 hours. The order of reaction is (NEET Kar. 2013)

For a reaction between A and B the order with respect to A is 2 and the order with respect to B is 3. The concentrations of both A and B are doubled, the rate will increase by a factor of: (NEET Kar. 2013)

What is the activation energy for a reaction if its rate doubles when the temperature is raised from 20°C to 35°C? (R = 8.314 J mol–l K–l) (NEET Kar. 2013)

For the reaction R P, -> the concentration of a reactant changes from 0.03 M to 0.02 M in 25 min. Calculate the average rate of reaction using units of time in seconds.

In a reaction, 2A ->products, the concentration of A decreases from 1.0 mol L-1 to 0.8 mol L-1 in 20 min. Calculate the rate during this interval.

Assertion (A) Δ[R] is multiplied with -1 to make the rate of the reaction a positive quantity. Reason (R) Δ[R] is a negative quantity in the expression rate of disappearance of R R t

Rate of a reaction can be expressed as I. The rate of decrease in concentration of any one of the reactants. II. The rate of increase in concentration of any one of the products. Which of the above mentioned statement…

The rate of formation of ammonia by the reaction : N2 + 3 H2 ⟶ 2 NH3 is expressed as d[NH ] dt = 2.5 × 10–4 mol L–1 s–1 . The rate of consumption of H2 expressed as d[H ] dt will be