Effect of temperature on gasphase chemical equilibria

Assume that the reaction entropy and enthalpy changes (AS° and AH°) appearing in the last term in Eq (9.21) are independent of temperature. Taking the logarithms of the first and last terms, and differentiating with respect to temperature yields:

This useful relation is known as the Van'tHoffequation. It can be shown to be valid even if AHo and ASo are temperature-dependent (see Problem 9.17). However, the discussions in Sects. 9.2 and 9.3 suggested that these reaction properties vary little with temperature, and in most cases can be treated as constants. According to Eq (9.25), a plot of experimental measurements in the form of lnKP Vs 1/T should be a straight line with a slope equal to -AHo/R.

Equation (9.25) is also the source of the following useful rules shown in Fig. 9.3.

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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