Chemistry Question Bank

1/2 t for a zero order reaction is …(I)… proportional to the initial concentration of the reactants and …(II)… proportional to the rate constant. Choose the correct words to fill up the blanks (I) and (II) respectivel…

…A… of the reaction is the time in which the concentration of a reactant is reduced to one half of its initial concentration. Choose the appropriate word to fill ‘A’ from the options given below.

For a given reaction half life period was found to be directly proportional to the initial concentration of the reactant. The order is

What will be the half-life of the first order reaction for which the value of rate constant is 200 s–1?

The half-life period of a first order reaction is

The square brackets in the expression Δ[R] = [R]2 – [R]1 are used to express …A… Here, A is

In a first order reaction, reactant concentration ‘C’ varies with time ‘t’ as

In a first order reaction the concentration of reactant decreases from 800 mol/dm3 to 50 mol/dm3 in 2 × 104 sec. The rate constant of reaction in sec–1 is:

For a first order reaction, (A) -> product the concentration of A changes from 0.1 M to 0.025 M in40 min. The rate of reaction when the concentration of A is 0.01 M is

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

For the reaction 4NH 5O 4NO 6H O, -> if the rate of disappearance of NH3 is 3.6 × 10–3 mol L-1 s–1, what is the rate of formation of H2O?

Similarly, the stoichiometric coefficient of D, A and B is 3,4 and 1 respectively. Thus using the concept, B D A C -> So, answer b is correct.

The rate of a reaction is expressed in different ways as follows : 1 d[C] 1 d[D] 1 d[A] d[B]. 2 dt 3 dt 4 dt dt The reaction is

For a hypothetical reaction, R -> products; rate k R . The negative sign used in the rate expression indicates

Choose the correct value of d NH dt for the reaction, N 3H 2NH -> (a) d H dt (b) d H dt (c) d N dt (d) d N dt Ans. (a) Sol. d NH d H dt dt

In order to express the rate at a particular moment of time we determine the …A… rate. Here A refers to

When the concentrations of gases is expressed in terms of their partial pressures, then the units of the rate of reaction will be

Find the value of from the graph shown below (a) av R r f (b) av R R r t t (c) av d R r dt (d) av R R r t t Ans. (d) Sol. av R R r t t

In the graph, slope is (a) inst d R r dt (b) inst d R r d P (c) inst d P r dt (d) inst d P r dt Ans. (c) Sol. Slope ⇒ inst d P r dt

...A… depends upon the change in concentration of reactants or products and the time taken for that change to occur. Here, A is

Rate of a reaction