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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: serjio on February 14, 2020, 02:15:35 PM

Title: Could you tell me how to solve this equation
Post by: serjio on February 14, 2020, 02:15:35 PM

The frequency factor is 6.31 x 108 M s-1 and the activation energy is 10 kJ/mol for the gas phase reaction: NO(g)+ O3(g)->NO2(g)+O2(g). Calculate the rate constant for this reaction at 370 K.

I try to use k= A e ^Ea/RT but it always wrong. Can anyone help me about this :'( :'(

Title: Re: Could you tell me how to solve this equation
Post by: MNIO on February 14, 2020, 03:40:37 PM

can you show your work?
do you have consistent units?
do you have a set of choices to pick from for answers?

Title: Re: Could you tell me how to solve this equation
Post by: Enthalpy on February 16, 2020, 07:09:16 PM

I doubt about the "+" in the exponential.

You should develop an intuition for that. Learning formulas doesn't work, you must re-establish and double-check every time whether + or -, * or /, and so on.

The activation energy slows down the reaction. So could the "+" possibly be correct?

Title: Re: Could you tell me how to solve this equation
Post by: MNIO on February 16, 2020, 11:06:27 PM

enthalpy...
   I usually write the arrhenius equation as
       k = Ao * exp(-Ea / RT)

regardless, I was hoping that Serjio was going to respond and show us his math with how he handled (or missed) that +/- term.  But he seems to have fled.  Too bad.

Title: Re: Could you tell me how to solve this equation
Post by: serjio on February 19, 2020, 04:11:08 PM

Quote from: Enthalpy on February 16, 2020, 07:09:16 PM

I doubt about the "+" in the exponential.

You should develop an intuition for that. Learning formulas doesn't work, you must re-establish and double-check every time whether + or -, * or /, and so on.uc browser (https://www.ucbrowser.vip/) shareit (https://shareit.onl/) appvn (https://appvn.onl/)


The activation energy slows down the reaction. So could the "+" possibly be correct?

agreed!!!

Title: Re: Could you tell me how to solve this equation
Post by: MNIO on February 19, 2020, 11:09:16 PM

Serjio...

you stated you tried to use the equation k = A * e^(Ea/RT) to calculate k but kept getting the wrong answer.  I asked you to show your work.  Where's the work?