Activation Energy

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Vanessa Romero-Campos 2B
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Joined: Fri Sep 25, 2015 2:00 am

Activation Energy

Postby Vanessa Romero-Campos 2B » Tue Feb 21, 2017 7:05 pm

Can someone explain why a reaction with very low activation energy has a rate that does not change much with temperature.

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Joined: Fri Jul 15, 2016 2:00 am

Re: Activation Energy

Postby Diana_Visco_1l » Tue Feb 21, 2017 9:33 pm

The larger this ratio, the smaller the rate (hence the negative sign.) This means that high temperature and low activation energy favor larger rate constants, and thus speed up the reaction. And because these terms occur in an exponent, their effects on the rate are quite substantial. Therefore, temperature has to be considerably large to have an effect with a low activation energy. If activation energy is low, a greater proportion of the collisions between reactants will result in reactions. If the temperature of the system is increased, the average heat energy is increased, a greater proportion of collisions between reactants result in reaction, and the reaction proceeds more rapidly. A catalyst increases the reaction rate by providing a reaction mechanism with a lower activation energy, so that a greater proportion of collisions result in reaction.

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Re: Activation Energy

Postby Nasir_Ahmed » Thu Feb 23, 2017 8:39 pm

So the rate stays relatively the same because a rise in temperature wouldn't help the reaction happen that much anyway because of the low activation energy?

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Re: Activation Energy

Postby edward_qiao_3I » Fri Feb 24, 2017 12:19 am

Yes. Essentially, because the activation energy is low already, not that much extra kinetic energy is needed to start the reaction, so increasing temperature (and therefore kinetic energy) does not do that much for the reaction

Magdalena Palavecino 1A
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Joined: Fri Sep 29, 2017 6:04 am

Re: Activation Energy

Postby Magdalena Palavecino 1A » Thu Feb 22, 2018 3:53 pm

If the amount of energy that is needed to make a reaction happen is small, then no matter how much you raise temperature, the reaction will occur regardless because it only needs a small increase in order to occur.

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