Answer KeyChemistry 223Quantitative Analysis LaboratoryPost‐lab Quiz9/24/101.Drying ensured that you could accurately weigh your KHP and your acid unknown. Why couldn't thesame procedure be used to make up a standard NaOH solution by drying solid NaOH, accuratelyweighing it, and dissolving it in water to avoid needing to do a KHP standardization?First, NaOH absorbs CO2, so the temperature would have to be high enough to decomposebicarbonate and carbonate into Na2O. That would also dehydrate NaOH into Na2O. This compoundis even more hygroscopic than NaOH (Na2O + H2O gives 2 NaOH). Second, Na2O could also soak upCO2from the air and directly form Na2CO3. Thus, drying is insufficient to generate a stable,weighable compound. One would have to store Na2O in vacuum and weigh it in vacuum to use it asa primary standard2.It's time to do a titration with NaOH. You obtain a buret, and find there is water clinging to theinside. You don't want that water to dilute your solution, and you realize that clinging drops are an
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pH meter, KHP, standard naoh solution, Analysis Laboratory Post‐lab