Can someone please explain the significance of pseudo rates and how they might appear in a kinetics question?
Thanks!
Pseudo Rates
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Re: Pseudo Rates
A pseudo-first-order rate is when a reaction is 2nd order overall but is first order with respect to two reactants. We use this when we need to make the reaction rate dependent on only one small concentration reactant.
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Re: Pseudo Rates
The pseudo rate constant makes it easier to determine a rate constant or reaction rate, since one concentration changes so little that it is negligible.
Hope this helps!
Hope this helps!
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Re: Pseudo Rates
Yes, adding on to the previous comments, this is a simple example of a pseudo-rate.
Rate = k[A][B]. k is a second-order rate constant. If there is excess of [B] compared to [A], then [B] will not change significantly during the reaction so it can be considered a constant. [B] can be absorbed into the rate constant, so we write Rate = k'[A] where k'=k[B] and k' is now a pseudo-first-order rate constant.
Rate = k[A][B]. k is a second-order rate constant. If there is excess of [B] compared to [A], then [B] will not change significantly during the reaction so it can be considered a constant. [B] can be absorbed into the rate constant, so we write Rate = k'[A] where k'=k[B] and k' is now a pseudo-first-order rate constant.
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Re: Pseudo Rates
Hi Isis!
The pseudo rate laws are used to help determine the rate constant in situations where there are multiple variables present. Isolating one variable in a psudo rate law can help simplify the total rate law for a reaction, eliminating unknowns. Hope this helps!
The pseudo rate laws are used to help determine the rate constant in situations where there are multiple variables present. Isolating one variable in a psudo rate law can help simplify the total rate law for a reaction, eliminating unknowns. Hope this helps!
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Re: Pseudo Rates
Pseudo rate laws is when the reaction is 2nd order overall but it's first order with respect to two reactants and the initial rate would depend on both A and B. They are helpful in determining the situations where there are multiple variables that are present. When you isolate one variable in a pseudo rate law, it can help you simplify the rate law of the reaction.
Re: Pseudo Rates
Pseudo-rates can be used to determine reaction rates in an experiment with multiple reactants where all except one of the reactants are in large excess.
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Re: Pseudo Rates
They are used when we have multiple reactants and want to determine the order of each one. In doing so, we focus on one reactant at a time and make the concentration of all the other reactants very high so that they essentially do not change and, thus, we can ignore them
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Re: Pseudo Rates
They are used when we have multiple reactants and want to determine the order of each one. In doing so, we focus on one reactant at a time and make the concentration of all the other reactants very high so that they essentially do not change and, thus, we can ignore them
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