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### rate constants

Posted: Sun Feb 25, 2018 10:40 pm
how are rate constants calculated and what do they represent?

### Re: rate constants

Posted: Sun Feb 25, 2018 10:43 pm
A rate constant represents how fast a chemical reaction will take place based on the concentrations of the reactants and products. You find it by plugging in the molar concentrations into your rate equation with their respective order and equaling it to the rate of the reaction.

### Re: rate constants

Posted: Sun Feb 25, 2018 10:48 pm
In addition to what is stated above, the rate constant k is independent of the concentrations of the reactants. You would multiply k by the concentrations to find the rate, but the concentrations themselves do not impact k.

### Re: rate constants

Posted: Sun Feb 25, 2018 10:52 pm
I would also like to add that k has different units for each type of order reaction. For example, k is in M/Ls for zero order equations and inverse seconds for first order equations. To find the units for k, set the reaction equal to M/Ls and solve for whatever units allow the units to end up as M/Ls

### Re: rate constants

Posted: Mon Feb 26, 2018 9:36 am
I'm also a little confused on the concept of K. In our notes it says K is dependent on temperature and activation energy. So if it's dependent, how is it a constant?

### Re: rate constants

Posted: Mon Mar 05, 2018 9:59 pm
Kayla Tchorz-Dis 1F wrote:I'm also a little confused on the concept of K. In our notes it says K is dependent on temperature and activation energy. So if it's dependent, how is it a constant?

The rate constant is constant in that it won't change under those specified conditions.

### Re: rate constants

Posted: Tue Mar 06, 2018 1:07 am
the rate constant is constant for a specific reaction at a specific temperature. If the reaction is different then the activation energy would be different, and if the temperature is different then that would influence K as well.

### Re: rate constants

Posted: Fri Mar 09, 2018 10:34 pm
They calculate the speed of the reaction