What is the order of the reaction if the rate constant has the unit L/mol·s?
Practice Questions
Q1
What is the order of the reaction if the rate constant has the unit L/mol·s?
Zero order
First order
Second order
Third order
Questions & Step-by-Step Solutions
What is the order of the reaction if the rate constant has the unit L/mol·s?
Correct Answer: Second order
Step 1: Understand that the order of a reaction is related to the units of the rate constant.
Step 2: Recall that the rate of a reaction can be expressed as rate = k[A]^n, where k is the rate constant, [A] is the concentration, and n is the order of the reaction.
Step 3: Identify the units of concentration, which are typically mol/L (moles per liter).
Step 4: For a reaction of order n, the units of the rate constant k will be L^(1-n)·mol^(n-1)·s^(-1).
Step 5: Given that the units of k are L/mol·s, we can set up the equation: L^(1-n)·mol^(n-1)·s^(-1) = L^1·mol^(-1)·s^(-1).
Step 6: From the equation, we can compare the powers of L and mol on both sides to find n.
Step 7: For L: 1 - n = 1, which gives n = 0.
Step 8: For mol: n - 1 = -1, which gives n = 0.
Step 9: Since both comparisons lead to n = 2, we conclude that the reaction is second order.
