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Ch.19 - Chemical Thermodynamics

Chapter 19, Problem 7b

The accompanying diagram shows how ΔH (red line) and TΔS (blue line) change with temperature for a hypothetical reaction.

(b) In what temperature range is this reaction spontaneous?

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Video transcript

Hello everyone in this video. We're given this diagram here where this yellow line represents delta H. And then this blue line here represents T delta us. The question being asked is to identify the range of temperatures where the reaction of course spontaneously. So let's go ahead and recall what the Gibbs free energy equation is. That's when delta G is equal to delta H minus T delta S. So from the further reaction to be spontaneous, you need the delta G value to be less than zero. So looking at this equation that we just wrote on top here, delta T, delta S has to be greater than delta H. So we see that when the temperature is greater than 4 50 kelvin's because to stay same, but this one keeps going up. So after this point here this will be greater than our delta H. So to answer his question then this temperature range that is going to be any temperature that is greater Then 450 Kelvin's. So this right here is going to be my final answer for this question.