However, somebody decided that we need to report it in percent. - pipette 5 ml sample into 250 mL flask To answer your question about sampling- you mentioned you swirl the tank with a paddle? affil. We currently test the acid tank and report it in oz/gal. Q. James, In a low concentration, nitric acid is often used in woodworking to artificially age pine and maple. 63.018g HNO3 + 39.998g NaOH --> 85g NaNO3 + 18.016g H2O The result of the first titration was done using this sample. Regards. Back to the general reaction: The mucic acid test gives a positive result with several galactose-containing substances such as lactose and dulcite. So this 5 ml sample that contains 3.275g HNO3 will need Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as white fuming nitric acid or red fuming nitric acid, the concentrations above 95%. A. Hi Jevetta. If you find +/- 1% difference, I wouldn't be too concerned at all. I was trying not to go nuts with the DEOX measurements, I wanted clean data. The good news is that Nitric acid is actually the required preservative for metals samples in aqueous solutions, and won't interfere at all with plasma spectrophotometry. I was not continually stirring this DEOX tank. Mark. This nitric acid titration is very difficult to get a normal looking graph over time. The Phth endpoint is really tricky. A condenser is used to condense the nitric acid fumes that bubble out of the solution. Second, you need to add the hydroxide very slowly as it will drop out the metals as hydroxides and they do not go back into solution very easily. Usually smaller samples mean more analytical error, and 0.5% is outstanding. For 60% nitric acid use 0.76 as the factor. - record the number of mL of 1.0N Sodium, Hydroxide used=V One general advice, for those lower concentrated solutions (and actually also for the 50% one): you better pipette 3 ml of the solution. Recap: However, if you want to know if you have nitric acid present, i.e. Check for any precipitation.if it gives white precipitates with barium chloride then that acid may be sulphuric acid, if it gives white precipitates with silver nitrate then that acid may be hydrochloric acid. (A well known industry standard) Q. - dilute to 150 mL with distilled water For the nitric, try 1 ml in a 250 ml beaker, add 75 mls DI water, titrate with 1.0 N sodium hydroxide to pH 3.57, giving titre A. A. Jim, 8 is way too high a pH as metal hydroxides will form and not go back into solution in any reasonable time frame. The discrepancy we have here is the interpretation of the end point ... different team members determine it at different points but we want to have a fail safe instruction/colour point. This is accomplished by adding a sample with silver nitrate solution and nitric acid to test if a white precipitate, silver chloride is present. You don't want to be in a very low range with your burette, as your absolute fault in the reading remains the same over the whole burette range, but get's relatively pretty big if you titrate so little. or. No doubt you've allowed yourself a pair of working ranges (target +/- some amount recommended by the manufacturer or your own experience, and then a narrower range like a warning limit) and your most simple, basic, goal for accuracy of the titration is to make sure that your titration error won't ever be enough to make you THINK you're in shop range when you're not, and that your adds will be accurate. Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.