Rate equations Flashcards
Define rate.
Change of concentration of products/reactants per unit time.
What are the units of rate.
mol/dm³
On a conc-time graph, what is the gradient of a tangent equal to?
Rate at that concentration.
What is the rate equation?
rate=k[A]^m [B]^n
What is k?
The rate constant.
How is k measured?
Experimentally.
What does the value of k depend on?
Temperature.
What are the units of k?
Dependent on reaction.
What are m and n?
Order of reaction.
What can the order of reaction be?
»0
»1 (first)
»2 (second)
What is overall order of a reaction?
Sum of all the powers/orders.
What effect does concentration have on rate at 0 order?
No effect.
How is 0 order written?
[X]⁰ - not written.
What effect does concentration have on rate at first order?
Linear effect.
How is first order written?
[X]¹ = [X]
What effect does concentration have on rate at second order?
Quadratic effect.
How is second order written?
[X]²
Describe a rate-concentration graph for 0 order.
Straight horizontal line.
Describe a rate-concentration graph for first order.
Straight positive diagonal line.
Describe a rate-concentration graph for second order.
Curved increasing line.
Describe a concentration-time graph for 0 order.
Straight negative diagonal line.
Describe a concentration-time graph for first order.
Curved decreasing shallow line.
Describe a concentration-time graph for second order.
Curved decreasing steep line.
What happens to rate concentration of temperature increases?
Rate constant increases exponentially.
