Can I clean my new nose piercing with contact solution?
Q. It's just a stud. And surprisingly, it didn't hurt at all! :) The one I have has the following in it: hydroxyalkyl phosphonate, boric acid, edetate disodium, polyoxyethylene polyoxypropylene block copolymer, ethylene diamine, sodium borate and sodium chloride. Preserved with polyaminopropyl biguanide 0.0001%.
Asked by Jeanine H - Wed Mar 10 20:35:59 2010 - - 1 Answers - 0 Comments

What would be the chemical reaction if Kjeldahl analysis was performed . . . .?
Q. A Kjeldahl analysis was performed upon a 0.1055g sample of impure biguanide C2H7N5. The liberated ammonia, collected in 40mL of 4% boric acid, was titrated with 20.10mL of 0.1200M HCl. What would be the preliminary and titration rxn? Calculate the %N present in the sample. My answer is 30% something can someone please check if im correct?
Asked by hannah - Mon Jul 6 08:25:03 2009 - - 1 Answers - 0 Comments

A. Reaction : N Containing Compound + Kjeldahl Catalyst ---> (NH4)2SO4 But you neutralize the reaction mixture with NaOH. So (NH4)2SO4 + 2NaOH ---> Na2SO4 + 2H2O + 2NH3. Thus, NH3 is liberated. Now, when NH3 is collected in H3BO3, the reaction will be, NH3 + H3BO3 ---> (NH4+) + (H2BO3-). When you neutralize this mixture with HCl, (The amount of H3BO3 is not important, as long as it is in excess.) (H2BO3-) + HCl ---> H3BO3 + (Cl-) H3BO3 is regenerated. Therefore, the moles of HCl consumed = Moles of H2BO3- generated = Moles of NH4 = Moles of Nitrogen (N atom) present in the sample. Now, the moles of HCl consumed = 20.1 x .12/1000 (I hope you already know this equation) = 0.002412 moles of N. Thus, the mass of N present in the… [cont.]
Answered by eagerfellow - Mon Jul 6 09:04:33 2009

Can I use this contact solution?
Q. Can I use the Member's Mark (Sam's Club) brand multi-purpose contact solution with my Acuvue Oasys contacts? My doctor reccomended Complete MPS but I was wondering if it's okay to use this... " # Three pack # Cleans & rinses # Removes protein # Disinfects & stores # No rub # Sterile # For use with Soft Contact Lenses Member's Mark Multi-Purpose Solution is a sterile isotonic buffered solution, preserved with polyaminopropyl biguanide (0.0001%), a phosphate buffer, Poloxamer 237, edetate disodium, sodium chloride, potassium chloride, and purified water. Member's Mark Multi-Purpose Solution contains no chlorhexidine or thimerosal. " Thanks
Asked by Kellyyyy - Mon Feb 23 20:38:10 2009 - - 1 Answers - 0 Comments