Question

Rate constant in case of first order reaction is:
A. Inversely proportional to the concentration units
B. Independent of concentration units
C. Directly proportional to concentration units
D. Inversely proportional to the square of concentration units

Answer 1

Hint: A reaction is supposed to be first order if its rate is determined by the difference in one concentration term as it were. One can say that a first order reaction is one whose rate fluctuates as the first power of the concentration of the reactant for example the rate increases as many times as the times the concentration of reactant is increased.

Complete step by step solution: The rate constant is the connection among rate and reactant concentrations. The rate constant isn't the rate, yet it permits you to decide the rate on the off chance that you know the reactant concentrations.
-Unit of rate constant for first order reaction \[\left( k \right)={{\min }^{-1}}{{s}^{-1}}\]
-The rate constant of a first order reaction has just a time unit. It has no concentration unit.
-This implies the numerical estimation of k for a first order reaction is independent of the unit in which concentration is communicated.
-On the off chance that the concentration unit is changed the numerical value of \[k\]for a first order reaction won't change.
-In any case, it would change with the change in time unit. State, \[k\]is \[6.0\times {{10}^{-3}}\min \] then it might likewise be composed as \[1\times {{10}^{-4}}{{s}^{-1}}\] for example numerical value of k will diminish multiple times if time unit is changed from anyway to minute or from minute to second.
For first order reaction,
Rate \[=k\left[ A \right],\]
\[k=\dfrac{mol/L}{\sec \times mol/L}={{\sec }^{-1}}\]

Hence, the correct option is B. Independent of concentration units.

Note: A first-order reaction relies upon the concentration of just a single reactant. In that capacity, a first-order reaction is at times alluded to as a unimolecular reaction. While different reactants can be available, each will be zero-order, since the concentration of these reactants don't influence the rate.