Recent content by FaNgS

I've done the first treatment with concentrated nitric acid but I only let it reflux for about 2 hours rather than the planned 24 hours. Pictures: http://i.imgur.com/X9rkgyP.jpg http://i.imgur.com/yBoIMC5.jpg http://i.imgur.com/oqg2XJc.jpg There was too much NO2 gas and even with two...

The setup will be condenser - tubing - drying tube - y or t connector - air supply in one connection - other connection with tubing to scrubbers. Wouldn't an air flow into my system, cause the gases to return backwards through the drying tube and into the condenser and reaction flask avoiding...

Based on the glassware I could find this is the setup I came up with: 1L 3-necked round bottomed flask (I couldn't find a regular 1L round bottomed flask) connected to an Allihn condenser, water in the bottom and out the top. Drying tube attached to one of the necks of the flask since you...

My final purpose is to introduce basic sites into my carbon just as you said. I am more or less going to follow the exact procedure listed in the article (just scaling up) but the use of benzene (or toluene) as a solvent is an issue as I explained. You seem to have a vast amount of knowledge and...

So without a stopper this means that I will be allowing any vapors escape my system and at the same time my liquid quantities will reduce. How do I properly control the mixtures and make sure it will not dry out while it's left overnight? It's great that you brought up cleanup and waste...

I will be treating carbon in 3 steps under reflux and I would really appreciate some suggestions, tips and advice on getting a proper and SAFE setup in the lab. I have at my disposal a fume hood and standard laboratory glassware. Treatment 1: 20g carbon treated with 100mL 65% Nitric Acid under...

This is exactly what I meant by back-titration. I would add different amount of HCl depending on the initial solution. So for example I will add 20ml of HCl to NaOH while I would add 30ml of HCl to Na2CO3 to ensure complete reaction because 2 moles of acid required to react with 1 mole of sodium...

Typically the time allowed for the carbon to remain in contact with the solutions is 24 hours and the maximum I've read is 72 hours. This is to allow enough time for the surface groups to get neutralized and from my experience to ensure that there is a measurable amount of titrant required to...

I standardized my NaOH solution with KHP and the concentration was 0.047M rather than the intended 0.05M. Is it acceptable to use the (now standardized) 0.047M NaOH solution to standardize my HCl solution. Then using the HCl solution to standardize the NaHCO3 and Na2CO3 solutions? A bit of...

For all the bases I used 99% or higher purity pellets (in the case of NaOH) or powder (NaHCO3 and Na2CO3). I calculated the mass required to achieve 0.05M and dissolved in the corresponding volume of distilled water I need in a volumetric flask.

Thank you. As you have noticed, even though Boehm titration is supposed to be a standard method, both papers have variations. Plus it seems they suggest a direct titration rather than a back-titration. I've tried performing a direct titration but it was difficult to get the same or almost the...

I'll double-check my calculations. As for my procedure I followed the general Boehm titration procedure as mentioned in this journal article: Standardization of the Boehm titration Part I CO2 expulsion and endpoint determination, S. L. Goertzen et. al, Carbon 48 (2010) 1252-1261. I'll...

I avoided the negative by subtracting the NaHCO3 titration from the Na2CO3 titration. I've been trying to figure it out, I'm not sure whether it's just my tiredness or do the numbers really don't make sense. You do agree that the results don't make sense, right?

I'm posting this here because I did not get much help from the Chemistry section. Please read further. Anyone familiar with the Boehm titration procedure and calculations? I've done the titrations based on what I was able to gather from literature and the calculations but the results don't...

Maybe someone can help me workout the calculations and if the science checks out, this is what I've gotten so far: After mixing separate batches of carbon with NaOH, NaHCO3 and Na2CO3 I will titrate directly the solution with HCl. In the case of NaOH titrated with HCl, at equilibrium moles...