Quick GenChem question

[hypemachine]

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Hi everyone,

I'd really appreciate it if anyone could clarify this for me.

In Chad's videos, he seems to use the phrase "rate constant" twice. The first is when he is talking about the equation Keq = [Products]/[Reactants]. He calls "Keq" the rate constant and says only temperature can affect it.

But then it seems like he also calls "k" the rate constant in the equation Rate = k[A]^x^y and in this instance, he says that either increasing the temperature OR decreasing the activation energy (assuming by a catalyst) can affect the "rate constant".

Now I'm confused...which one is ACTUALLY the rate constant, and what effects it? I thought only temperature did, but now I don't know if Keq is the rate constant or if "k" is.

 

[LazyP]

Applies to different things. Keq (equilibrium constant) deals with equilibriums, solutions, and what not. The rate constant, k, deals with kinetics; how fast the reactions occur.

 

[hypemachine]

Ok I think with your answer (and a little extra reading) I get it now. So Keq can only be changed by temperature, and k can be changed by lowering the Ea or increasing the temperature. Is that right? haha

 

[dent777]

Both Keq and k (rate constant) are affected by T, however, only k(rate constant) is affected by energy of activation.

 

[hypemachine]

Both Keq and k (rate constant) are affected by T, however, only k(rate constant) is affected by energy of activation.

Perfect. Thanks so much to you and LazyP!