Determining reaction order

[Gabriel Barcelona 2L]

How is reaction order determined? What does the number behind the order signify and how can you identify the order based on graphs (linear vs. exponential) specifically with first order reactions?

[Angelina Tran 2F]

Reaction order represents the number of species whose concentration directly affects the rate of reaction. It can be obtained by adding all the exponents of the concentration terms in the rate expression. The reaction plotted against different Y-axes is used to determine the order of a reaction. If the line is straight when the Y-axis is concentration, the reaction is zero order. If the line is straight when the Y-axis is ln(concentration), the reaction is first order.

[Stephanie_manasyan]

Hi! You can determine reaction order by calculating the overall order of a reaction from the given equations and the rate law, or by observing the units and if given, a graph. The units from 0,1st, and 2nd order reactions differ and second order plots are positive while 0 and 1st order have a negative slope (slope=-k while 2nd order slope=k) Hope this helps!

[106062642]

The exponent to which the concentration of a reactant is raised in the rate equation is indicated by the number behind the order. For instance, the reactant concentration is increased to the power of one in a first-order reaction. Plotting the natural logarithm of concentration vs. time yields a straight line for first-order reactions, which makes graphic analysis very helpful for determining reaction order.