Snapshot 1: rate of reaction with a high energy of activation
Snapshot 2: rate of reaction with a low energy of activation
Snapshot 3: effect of temperature on viscosity of a Newtonian fluid
This Demonstration shows the temperature dependence of reaction rates or viscosity according to the Arrhenius equation,
is the temperature,
is a reference temperature (both in K),
are appropriate parameter values at the respective temperatures,
is the "energy of activation" (in J, kJ, cal, or kcal per mole), and
is the universal gas constant. If
is positive, as in most chemical and biochemical reactions,
rises with temperature; if negative,
decreases with temperature, which is usually the case for viscosity.
The Demonstration plots the
relationship on a linear scale (top), with the corresponding
plot (bottom). The value of
at the chosen temperature is shown as a blue dot on both plots and its numerical value is shown above the top plot.
The values of the parameters can be entered directly or by moving the slider. The maximum value of the
axes can also be adjusted. The order of magnitude of
may be selected from a popup menu. Not all allowed settings produce plots that correspond to physical systems.
D. Purich and R. D. Allison, Handbook of Biochemical Kinetics
, San Diego, CA: Academic Press, 2000.
G. Drobny, P. Reid, and T. Engel, Physical Chemistry for the Life Sciences,
Upper Saddle River, NJ: Prentice Hall, 2008.