What is the unit of the rate constant k for a first-order reaction?
Practice Questions
Q1
What is the unit of the rate constant k for a first-order reaction?
mol/L·s
s^-1
mol/L
L^2/(mol·s)
Questions & Step-by-Step Solutions
What is the unit of the rate constant k for a first-order reaction?
Step 1: Understand that a first-order reaction means the rate of the reaction depends on the concentration of one reactant.
Step 2: The rate of a reaction is usually expressed in terms of concentration change over time, which has units of mol/L/s (moles per liter per second).
Step 3: For a first-order reaction, the rate can be written as Rate = k[A], where [A] is the concentration of the reactant.
Step 4: Rearranging the equation gives k = Rate / [A].
Step 5: Substitute the units into the equation: k = (mol/L/s) / (mol/L).
Step 6: Simplifying the units: (mol/L/s) divided by (mol/L) gives s^-1.
Step 7: Therefore, the unit of the rate constant k for a first-order reaction is s^-1.
