Preparing a solution of primary standard Essay

PurposeThe purpose of this experiment is to to prepare a solution of primary standard of potassium hydrogenphthalate C8H5O4K, which can be apply to standardise piddle-soluble bases such as sodium hydroxide solution. expressionn= m/M and c= n/V theoryMany common reagents are supplied in an impure state or they can easily pick up moisture from the atmosphere, or may be supplied as concentrated solutions of an uncertain concentration. As a consequence, solutions make from such substances must be stanardised against a substance of known purity. We presage them primary standards.Chemicals Potassium hydrogenphthalate (C8H5O4K)Apparatus top loading balance ( unhurriedness scale) weighing bottleful beaker wadtric flaskProcedure We started by weighing 5 g of potassium hydrogenphthalate accurately in a weighing bottle. I poured the content of the weighing bottle into a beaker and i reweighed the the weighing bottle. I to a fault made certainly that no residue of the chemical was remaini ng in the weighing bottle. I added about 100 ml of distilled water to the beaker and stired it until it dissolved the hydrogenphthalate. I transferred the solution from the beaker to a 250 cm3 voumetric flask. i washed the beaker some(prenominal) times and poured the content into the volumetric flask just to make sure that no residue of the chemical was left in the beaker. I go under in more distilled water in the volumetric flask until the volume was 250 cm3 and mixed it thoroughly. I labeled my flask with my initials, date and content.Data tip of weighing bottle and hydrogenphthalate 5.964 gVolume of solution 250 cm3Calculation chain reactor of weighing bottle and content 5.96 +_ 0.01gmass of weighing bottle .96 +_ 0.01 gmass of C8H5O4K uncertainity 0.01+0.01= +_0.02 bomber mass of potassium hydrogen phtalate 0.01g/molmolar mass of potassium hydrogenphthalate.204.286 g/mol +_ .2 +_ .089 %mass of weighing bottle and contents, m15.964 g +- .001mass of weighing bottle, m20.962 g + _ .001mass of potassium hydrogenphthalate m=m1-m25.002 g +_ .002 +_ 0.385%amount of potassium hydrogenphthalate, n= m/M0.024 moles +_0.475%We also know the volume of the solution to be 25 dm3, so displace every last(predicate) these values in the formula. uncetainty for volume +_ 0.0005%c = n/Vso concentration of potassium hydrogenphthalate c= 0.09612 mol/dm3% uncertainty 0.00012%+0.475%= .47512% misgiving/ErrorTap water contains chemicals and other impurities and is not suitable for qualification up solutions so we should always use distilled water for making solution. i have also noted margin of error of different appratus and all calculations have been made keeping in mind the margin of error.