3.1.9 Rates of Reaction

Information on calculating rate from a graph

The rate Equations and orders

The rate equation links rate with …3? Of …4?

1. What is the rate equation?

2. What are the name units for each symbol?

3. Concentrations. 4. Substances

1. Rate = k [A]^a [B]^b

2. Rate of reaction measured in Moldm-3 s-1

   K= Rate constant (units vary)

   [A] [B] = Concentration of substance

   a and b = Orders of the reaction

1. Answer image question

   Note: The units for Rate is always Moldm-3 s-1

   Note: The only time units vary is with The rate constant (K)

1. Answer image question

   Note: You don’t include the concentrations with zero order in your calculation because the don’t affect the rate

1. Answer image question but only calculate the rate equation.

   Note: We don’t need to put the 1 indice if the concentrations in the rate equation is first order.

Now calculate the initial rate for experiment 4? (Answer in back image)

Answer image question?

What are the iodine clock experiment steps To measure rate of reaction? (In this image)

2. How can the rate of reaction be measured in the following experiments

   • The change in pH of a reaction

   • Amount of mass loss

   • Volume if gas produced

Note: Do not get Concentration-time and Rate-Concentration graphs mixed up. You can make Rate-Conc graphs by finding the gradients of various points in a Conc-time graph then plotting the points on a Rate-conc graph.

Answer image question

Answer is step 2 because it’s at this step where we finish scoring off the molecules.

Answer image question

The Arrhenius equation links activation energy and temperature to …1?

Rate constant (K)

Answer image question?

Note: Learn the rearranged version aswell to make it easier

Working out Activation energy and Arrhenius constant

Note: The exponential button on the calculator is shift ln