Chemical Equilibrium - Effect of Temperature

Effect of Temperature

The effect of changing temperature on an equilibrium constant is given by the van 't Hoff equation

Thus, for exothermic reactions, (ΔH is negative) K decreases with an increase in temperature, but, for endothermic reactions, (ΔH is positive) K increases with an increase temperature. An alternative formulation is

At first sight this appears to offer a means of obtaining the standard molar enthalpy of the reaction by studying the variation of K with temperature. In practice, however, the method is unreliable because error propagation almost always gives very large errors on the values calculated in this way.

Read more about this topic:  Chemical Equilibrium

Famous quotes containing the words effect of, effect and/or temperature:

    The effect of liberty to individuals is that they may do what they please: we ought to see what it will please them to do, before we risk congratulations.
    Edmund Burke (1729–1797)

    A readiness to believe ill of others, before we have duly examined it, is the effect of laziness and pride. We are eager to find a culprit, and loath to give ourselves the trouble of examining the crime.
    François, Duc De La Rochefoucauld (1613–1680)

    This pond never breaks up so soon as the others in this neighborhood, on account both of its greater depth and its having no stream passing through it to melt or wear away the ice.... It indicates better than any water hereabouts the absolute progress of the season, being least affected by transient changes of temperature. A severe cold of a few days’ duration in March may very much retard the opening of the former ponds, while the temperature of Walden increases almost uninterruptedly.
    Henry David Thoreau (1817–1862)