Read the passage carefully and answer the questions based on the passage:
The number of reacting species (atoms, ions or molecules) taking part in an elementary reaction, which must collide simultaneously in order to bring about a chemical reaction is called molecularity of a reaction. In the rate equation Rate = $k [A]^x [B]^y$
$x$ and $y$ indicate how sensitive the rate is to the change in concentration of A and B, respectively. Sum of these exponents, i.e., $x + y$ gives the overall order of a reaction where $x$ and $y$ represent the order with respect to the reactants A and B, respectively. Hence, the sum of powers of the concentration of the reactants in the rate law expression is called the order of that chemical reaction. For a first order reaction, the concentration of the reactant varies as $[R] = [R]_0e^{-kt}$
The units of first and zero order rate constant of reactions are respectively:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $s^{-1}, Ms^{-1}$
Correct units:
|
Order of reaction |
Rate = k [A]ⁿ |
Unit of rate constant (k) |
|
Zero order |
Rate = k |
$mol\, L^{-1}\, s^{-1}→ M\, s^{-1}$ |
|
First order |
Rate = k [A] |
$s^{-1} → s^{-1}$ |
|
Second order |
Rate = k [A]² |
$L\,mol^{-1}\, s^{-1} =M^{-1}\,s^{-1}$ |
So the correct sequence is:
First order → $s^{-1}$ Zero order → $M\,s^{-1}$