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Topic: Kinetics of the Permanganate-IP reaction prelab help.  (Read 8554 times)

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Offline kbought1

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Kinetics of the Permanganate-IP reaction prelab help.
« on: February 02, 2011, 06:44:52 PM »
Alright, I just want to know how to figure out how to do this, I don't want the answers, I just would like to know how. if you want you can change the numbers, and show how to do it with formulas or what not... even just give me the formulas and I will do it myself, I really don't care.... Please Help !!!!!!

For the solution you will make in step 14 of the experimental procedure:
a) Calculate the mL of isopropyl alcohol you will need.
b) Calculate the mL of 9.0 M sulfuric acid you will need.
c) Calculate the g of sodium fluoride you will need.
Hint: Necessary molar masses and densities for the above reacents are given in the REAGENTS PROVIDED section of the experiment
Regents provided:
KMnO4, 2.00x10-3M
Sulfiric Acid 1.00 M
Sulfiric Acid 6.0 M
Sulfiric Acid 9.0 M
Isopropyl alcohol, 100%, 60.096 g/mol, 0.782 g/mL at 25 deg C
NaF, solid, 41.988 g/mol

Step 14. Prepare 100.o mL of a solution which is 0.60 M in isopropyl alcohol, 0.120 M in NaF, and 1.00 M in H2SO4.
In a 100 mL volumetric flask, mix the g of NaF and the volumes of 9.0 M H2SO4 and pure isopropyl alcohol that you calculated in the prelab exercise

Offline rabolisk

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #1 on: February 02, 2011, 07:11:53 PM »
This is just a huge dimensional analysis problem essentially.

I would first define what molarity means and go from there. What you are trying to do is put x moles of isopropyl alcohol, y moles of NaF and Z moles of sulfuric acid in a 100.0 mL solution. Show me how you would start this.

Offline kbought1

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #2 on: February 02, 2011, 07:17:52 PM »
This is just a huge dimensional analysis problem essentially.

I would first define what molarity means and go from there. What you are trying to do is put x moles of isopropyl alcohol, y moles of NaF and Z moles of sulfuric acid in a 100.0 mL solution. Show me how you would start this.

alright well, I need to have 0.60 M of isopropyl alcohol. so.
you have .6 M= .6M*1L/1000ml=.0006 mol/ml
you multiply that by 100 to find that you need .06 moles
then you times that by 60.096 g/ mol and divide by 0.782, but it says I am wrong...

Offline rabolisk

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #3 on: February 02, 2011, 07:36:38 PM »
Make sure to check your sig figs.

Offline kbought1

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #4 on: February 02, 2011, 08:07:28 PM »
okay, I got 11 for b. but how do I figure out c and a?
for C. I need 0.120 M of NaF
and the molar mass is 41.988
and I get 5 grams, but it's not right...

Offline rabolisk

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #5 on: February 02, 2011, 08:22:43 PM »
For C you did the math wrong.

For A, make sure you use correct sig figs.

Offline kbought1

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #6 on: February 02, 2011, 08:24:29 PM »
For C you did the math wrong.

For A, make sure you use correct sig figs.

alright this is the info I have for c
0.120 M of NaF is the end result, x amount of grams is dissolved in 50mL of h20, and the molar mass is 41.988
how do I set this up?

Offline rabolisk

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #7 on: February 02, 2011, 08:34:08 PM »
Where are you getting 50 mL of H2O from??

Offline kbought1

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #8 on: February 02, 2011, 08:35:44 PM »
it was in the prelab, I didn't read it until step 15, but thats what it said...

Offline rabolisk

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Re: Kinetics of the Permanganate-IP reaction prelab help.
« Reply #9 on: February 02, 2011, 08:43:27 PM »
It won't matter for this problem. What you need to do is go from 1.20 M to moles of NaF to mass of NaF.

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