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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Khem on March 31, 2015, 02:04:11 AM

Title: Trying to determine rate constant from lab
Post by: Khem on March 31, 2015, 02:04:11 AM

Hi everyone,

During a recent lab, I added 5 mL of [0.8] KI to a reaction solution of 13 mL H2O, 6 mL of H2O2, and 1 mL of [0.2] NaOH.

I've been trying to figure out the molarity of I- accounting for dilution when KI was added to the solution...do you know how to do this? If you could show me, you d be a tremedous help to this undergrad!

If you need more info, please let me know.

In context: I have a first order reaction in I- and the formula I'm working with is:

K=K'/[I-] where K' is -0.1238.

Thanks so much!

Title: Re: Trying to determine rate constant from lab
Post by: sjb on March 31, 2015, 02:43:27 AM

Quote from: Khem on March 31, 2015, 02:04:11 AM

Hi everyone,

During a recent lab, I added 5 mL of [0.8] KI to a reaction solution of 13 mL H2O, 6 mL of H2O2, and 1 mL of [0.2] NaOH.

I've been trying to figure out the molarity of I- accounting for dilution when KI was added to the solution...do you know how to do this? If you could show me, you d be a tremedous help to this undergrad!

If you need more info, please let me know.

In context: I have a first order reaction in I- and the formula I'm working with is:

K=K'/[I-] where K' is -0.1238.

Thanks so much!

What is the definition of molarity?

Title: Re: Trying to determine rate constant from lab
Post by: Khem on March 31, 2015, 03:08:21 AM

Molarity being the molar concentration of I-, or [I-].

Title: Re: Trying to determine rate constant from lab
Post by: sjb on March 31, 2015, 05:41:27 AM

Quote from: Khem on March 31, 2015, 03:08:21 AM

Molarity being the molar concentration of I-, or [I-].

How is molar concentration calculated?

Title: Re: Trying to determine rate constant from lab
Post by: Khem on April 01, 2015, 01:18:30 AM

I would divide moles over liters, in which case I imagine I need to convert mL to liter for some component   ???