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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: mrvegas22 on December 19, 2005, 08:48:10 PM

Title: how much baking soda and vinegar will you need to FULLY fill a ziplock bag up?
Post by: mrvegas22 on December 19, 2005, 08:48:10 PM
EXACTLY how much baking soda and vinegar will you need to FULLY fill a ziplock bag up with out popping it or under-flating it?

I am really confused. That is all our teacher told us and he said that we need to be prepared with a procedure for a lab tommorow. I know it deals with stokiometry but dont know where to go from there. We know we can find the volume of the bag by filling it with water and emptying the water into a beaker.

WHAT DO I DO NEXT? help greatly appreciated!

I know that i need to find the volume of the bag first, but all i need are some gas formulas and a procdure/instructions.

he gave us this formula...
CH3COOH + NaHCO3 --> CO2 +H2O + NaCH3COO

atomic masses:
CH3COOH - 60.05
NaHCO3 - 84.06
CO2 - 44.01
H2O - 18.02
NaCH3COO - 82.25

THANKS IN ADVANCED ???
Title: Re:vinegar and baking soda lab... PLEASE HLEP ASAP
Post by: constant thinker on December 19, 2005, 09:43:31 PM
Why don't you just take some vinegar and baking soda and then try it at your house in a zip lock bag. From my expierences I can tell you probably a few grams (like 2-4g) of baking soda in some vinegar (like 4-8ml) should fill up a decent size bag and make stiff but not explode. If your looking for an equation to figure this out, I'm sorry but I'm no help there. Also you should try to almost fully deflate the bag.

Just play around with things. Best way to learn in my opinion.
Title: Re:vinegar and baking soda lab... PLEASE HLEP ASAP
Post by: mrvegas22 on December 19, 2005, 09:55:21 PM
Why don't you just take some vinegar and baking soda and then try it at your house in a zip lock bag. From my expierences I can tell you probably a few grams (like 2-4g) of baking soda in some vinegar (like 4-8ml) should fill up a decent size bag and make stiff but not explode. If your looking for an equation to figure this out, I'm sorry but I'm no help there. Also you should try to almost fully deflate the bag.

Just play around with things. Best way to learn in my opinion.

Thanks, i would but my chem teacher is expecting a full formula and work to be shown. i need the math part of it too, unfortunatly.
Title: Re:vinegar and baking soda lab... PLEASE HLEP ASAP
Post by: Chrataxe on December 25, 2005, 08:11:02 AM
You could always use densities.
Title: Re:how much baking soda and vinegar will you need to FULLY fill a ziplock bag up
Post by: jdurg on December 25, 2005, 02:30:29 PM
This is a simple question.  First of all, you need to figure out the volume of the zip-loc baggie and you can do that by filling it with water and then measuring the volume of water you used.  Now that you know the volume of the bag, you will know how much gas is needed to fill up the bag.  In the reaction given to you, you can see that the reaction between acetic acid (vinegar) and sodium bicarbonate (baking soda) will result in the release of CO2 gas.

With the volume known, you can use the ideal gas law (PV=nRT) to calculate the number of moles of CO2 gas you will need to obtain that volume.  When you calculate the moles you can calculate the mass of sodium bicarbonate needed.  This will tell you how much baking soda is needed.  You should then be able to figure out the rest yourself.   ;D