sharylc Posted April 12, 2011 Report Share Posted April 12, 2011 HiHow long does vinegar need to be exposed to the atmosphere for to see a change in concentration of CH3COOH? Is it a matter of hours or days?Thanks! Reply Link to post Share on other sites More sharing options...
Drake Glau Posted April 12, 2011 Report Share Posted April 12, 2011 Type of vinegar? It matters =/ Also, are you just looking for the volatility of the vinegar or are you actually doing something with it besides leaving it in a beaker to evaporate? O.o Reply Link to post Share on other sites More sharing options...
~pauline~ Posted April 12, 2011 Report Share Posted April 12, 2011 Type of vinegar? It matters =/ Also, are you just looking for the volatility of the vinegar or are you actually doing something with it besides leaving it in a beaker to evaporate? O.oWe are looking at the acetic acid in the vinegar, so it will be CH3COOH. The solution is meant to be expose to air for long enough so we can see the change in the concentration. Just not sure about what's the minimum time for exposure. If you can help that will be great. Reply Link to post Share on other sites More sharing options...
bulareo Posted April 30, 2011 Report Share Posted April 30, 2011 I did one Vinegar titration two days before and the "experiment" was ok... But I stuck on calculating the concentration of vinegar. Can anyone help me how to calculate the concentration??.( it will be awesome if someone give me the example)Thank youReo year 12, Reply Link to post Share on other sites More sharing options...
dessskris Posted April 30, 2011 Report Share Posted April 30, 2011 well it depends on what you did and what is known tell us what data you have and what you reacted. Reply Link to post Share on other sites More sharing options...
Guest 1529 Posted April 30, 2011 Report Share Posted April 30, 2011 (edited) I did one Vinegar titration two days before and the "experiment" was ok... But I stuck on calculating the concentration of vinegar. Can anyone help me how to calculate the concentration??.( it will be awesome if someone give me the example)Thank youReo year 12,Since it's a liquid, you should use the formula moles = concentration x volume. the thing is, that you need to know at least 2 of them so the concentration of vinegar must be written in the bottle where you took it from... unless you know the number of moles and you certainly had the volume fixed so all you have to do is to use that formula. If you don't understand it yet, ask again =)MergedHiHow long does vinegar need to be exposed to the atmosphere for to see a change in concentration of CH3COOH? Is it a matter of hours or days?Thanks!Probably 2 or 3 days because it takes time to decompose. Edited April 30, 2011 by Keel Merged post Reply Link to post Share on other sites More sharing options...
Drake Glau Posted April 30, 2011 Report Share Posted April 30, 2011 (edited) I did one Vinegar titration two days before and the "experiment" was ok... But I stuck on calculating the concentration of vinegar. Can anyone help me how to calculate the concentration??.( it will be awesome if someone give me the example)Thank youReo year 12,You need to know what in the vinegar is reacting (like acetic/ethanoic acid) and then what base you used to neutralize. From this you can figure out your chemical equation. You also need to know the original volume of your vinegar that was in the flask under the burrete. You'll also the volume of the vinegar and it's concentration. K, first thing you need to do is find out how many moles of the base it took to neutralize. Use c=n/v to do so since you know c and v already. After this (because you know the chemical equation) you can find the mole ratio which will tell you how many moles of base it takes to neutralize the acid. If it takes 2 moles of base for 1 mole of acid then you can take the moles of the base and divide it by 2 to find the amount of moles of acid it reacted with. If it's 1:1 then they just equal. It one mole of base reacts with 2 moles of acid you multiply your bases moles by 2 to find the moles of the acid (I'm hoping you picked up on the trend ). After you have how many moles of acid were present in your flask you can use c=n/v where n is the moles you just calculated for the acid and v is the original volume of acid you started out with Edited April 30, 2011 by Drake Glau Reply Link to post Share on other sites More sharing options...
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