PreparationofpHbuffersolutionsAnalChemresourcesexweb10!04!1613!08!07pdf (1)

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PreparationofpHbuffersolutionsAnalChemresourcesexweb10!04!1613!08!07pdf (1)
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  Preparation of pH buffer solutions(AnalChem resources,ex web10-04-1613-08-07docx).docx  (Umschreibung von .mht auf .word.docx & .pdf) Von:   D:\REZ-EM\EM-TEM anal\PUFFER & rel\Preparation of pH buffer solutions(AnalChem resources,ex web10-04-16mht).mht Preparation of pH buffer solutions Email   Phosphate and Acetate buffers The different names for phosphate salts. Standardization buffers pH 4 and pH 7. Ph range of some buffer systems. Making up buffer solutions by adding an adjuster solution (acid or base) to a known volume and concentration of a primary salt solution. Potassium hydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, potassium hydrogen phthalate, sodium acetate,sodium tetraborate, tris aminomethane. Related link: Analysis Buffers  For EDTA titrations For Fluoride (TISAB) For Determination of Fe. On this page: Click the links below to jump to the relevant info: The preparation of pH buffer solutions   acetate buffers   phosphate buffers   solid mixture buffers   Phosphates Phosphate salts are known by several names and the correct phosphate must be used to prepare buffer solutions. One phosphate cannot be substituted for another phosphate. Check formula of salt to be certain. Formula Name of salt Other names KH 2 PO 4  potassium dihydrogen phosphate potassium dihydrogen orthophosphate monobasic potassium phosphate monopotassium phosphate acid potassium phosphate potassium biphosphate K 2 HPO 4  potassium hydrogen phosphate dipotassium hydrogen orthophosphate dipotassium hydrogen phosphate dibasic potassium phosphate dipotassium phosphate K 3 PO 4  potassium phosphate tribasic potassium phosphate tripotassium phosphate Standardization buffers For pH=7.00 :   Add 29.1 ml of 0.1 molar NaOH to 50 ml 0.1 molar potassium dihydrogen phosphate.  Alternatively : Dissolve 1.20g of sodium dihydrogen phosphate and 0.885g of disidium hydrogen phosphate in 1 liter volume distilled water. For pH= 4.00 :   Add 0.1 ml of 0.1 molar NaOH to 50 ml of 0.1 molar potassium hydrogen phthalate .  Alternatively : Dissolve 8.954g of disodium hydrogen phosphste.12 H 2 O and 3.4023g of potassium dihydrogen phosphate in 1 liter volume distilled water. Range of common buffer systems ¹      Range of common buffer systems ¹   Buffering system Useful buffering pH range @ 25°C Hydrochloric acid/ Potassium chloride 1.0 - 2.2 Glycine/ Hydrochloric acid 2.2 - 3.6 Potassium hydrogen phthalate/ Hydrochloric acid 2.2 - 4.0 Citric acid/ Sodium citrate 3.0 - 6.2 Sodium acetate/ Acetic acid 3.7 - 5.6 Potassium hydrogen phtaalate/ Sodium hydroxide 4.1 - 5.9 Disodium hydrogen phthalate / Sodium dihydrogen orthophospate 5.8 - 8.0 Dipotassium hydrogen phthalate / Potassium dihydrogen orthophospate 5.8 - 8.0 Potassium dihydrogen orthophosphate / sodium hydroxide 5.8 - 8.00 Barbitone sodium / Hydrochloric acid 6.8 - 9.6 Tris (hydroxylmethyl) aminomethane / Hydrochloric acid 7.0 - 9.00 Sodium tetraborate/ Hydrochloric acid 8.1 - 9.2 Glycine/ Sodium hydroxide 8.6 - 10.6 Sodium carbonate/ Sodium hydrogen carbonate 9.2 - 10.8 Sodium tetraborate/ Sodium hydroxide 9.3 - 10.7 Sodium bicarbonate / Sodium hydroxide 9.60 - 11.0 Sodium hydrogen orthophosphate / Sodium hydroxide 11.0 - 11.9 Potassium chloride/ Sodium hydroxide 12.0 - 13.0 Preparing a Buffer Solution ²   Preparing a Buffer Solution ²   This page gives tabulated info on the preparation of buffers by mixing adjusters with a known volume of the primary salt solution, and made up to 200ml with distilled water. BUFFERS 1.00 - 9.00 Buffer A : pH 1.0 - 2.2 Buffer B : pH 2.2 - 4.00 Buffer C : pH 4.10 - 5.90 Buffer D : pH 5.8 - 8.00 Buffer E : pH 7.0 - 9.00 50 ml 0.2 M KCl + mls of 0.2 M HCl 100 ml 0.1 M potassium hydrogen phthalate + mls of 0.1 M HCl. 100 ml 0.1 M potassium hydrogen phthalate + mls of 0.1 M NaOH . 100 ml 0.1 M KH2PO4 + mls of 0.1 M NaOH. 100 ml 0.1 M tris (hydroxymethyl) aminomethane + mls of 0.1 M HCl. pH mls of 0.2M HCl added pH mls of 0.1M HCl added pH mls of 0.1M NaOH added pH mls of 0.1M NaOH added pH mls of 0.1 M HCl added 1.00 134.0 2.20 99.0 4.10 2.6 5.80 7.2 7.00 93.2  1.10 105.6 2.30 91.6 4.20 6.0 5.90 9.2 7.10 91.4 1.20 85.0 2.40 84.4 4.30 9.4 6.00 11.2 7.20 89.4 1.30 67.2 2.50 77.6 4.40 13.2 6.10 13.6 7.30 86.8 1.40 53.2 2.60 70.8 4.50 17.4 6.20 16.2 7.40 84.0 1.50 41.4 2.70 64.2 4.60 22.2 6.30 19.4 7.50 80.6 1.60 32.4 2.80 57.8 4.70 27.2 6.40 23.2 7.60 77.0 1.70 26.0 2.90 51.4 4.80 33.0 6.50 27.8 7.70 73.2 1.80 20.4 3.00 44.6 4.90 38.8 6.60 32.8 7.80 69.0 1.90 16.2 3.10 37.6 5.00 45.2 6.70 38.6 7.90 64.0 2.00 13.0 3.20 31.4 5.10 51.0 6.80 44.8 8.00 58.4 2.10 10.2 3.30 25.8 5.20 57.6 6.90 51.8 8.l0 52.4 2.20 7.8 3.40 20.8 5.30 63.2 7.00 58.2 8.20 45.8 3.50 16.4 5.40 68.2 7.10 64.2 8.30 39.8 3.60 12.6 5.50 73.2 7.20 69.4 8.40 34.4 3.70 9.0 5.60 77.6 7.30 74.0 8.50 29.4 3.80 5.8 5.70 81.2 7.40 78.2 8.60 24.4 3.90 2.8 5.80 84.6 7.50 82.2 8.70 20.6 4.00 0.2 5.90 87.4 7.60 85.6 8.80 17.0 7.70 88.4 8.90 14.0 7.80 90.6 9.00 11.4 7.90 92.2 8.00 93.4 ./. BUFFERS 08 - 13  BUFFERS 08 - 13 Buffer F: pH 8.0 - 9.10 Buffer G : pH 9.2 - 10.80 Buffer H : pH 9.60 - 11.00 Buffer I : pH 10.90 - 12.00 Buffer J : pH 12.00 - 13.00 100 mL 0.025 M Na2B4O7.10H2O (borax) + mls of 0.1 M HCl. 100 mL 0.025 M Na2B4O7.10H2O (borax) + mls of 0.1 M NaOH. 100 mL 0.05 M NaHCO3 + mls of 0.1 M NaOH. 100 mL 0.05 M Na2HPO4 + mls of 0.1 M NaOH. 50 mL 0.2 M KCl + volume indicated (in mL) 0.2 M NaOH. pH mls of 0.1M HCl added pH mls of 0.1M NaOH added pH mls of 0.1M NaOH added pH mls of 0.1M NaOH added pH mls of 0.2M NaOH added 8.00 41.0 9.20 1.8 9.60 10.0 10.90 6.6 12.00 12.0 8.10 39.4 9.30 7.2 9.70 12.4 11.00 8.2 12.10 16.0 8.20 37.6 9.40 12.4 9.80 15.2 11.10 10.2 12.20 20.4 8.30 35.4 9.50 17.6 9.90 18.2 11.20 12.6 12.30 25.6 8.40 33.2 9.60 22.2 10.00 21.4 11.30 15.2 12.40 32.4 8.50 30.4 9.70 26.2 10.10 24.4 11.40 18.2 12.50 40.8 8.60 27.0 9.80 30.0 10.20 27.6 11.50 22.2 12.60 51.2 8.70 23.2 9.90 33.4 10.30 30.4 11.60 27.0 12.70 64.4 8.80 19.2 10.00 36.6 10.40 33.0 11.70 32.4 12.80 82.4 8.90 14.2 10.10 39.0 10.50 35.6 11.80 38.8 12.90 106.0 9.00 9.2 10.20 41.0 10.60 38.2 11.90 46.0 13.00 132.0 9.10 4.0 10.30 42.6 10.70 40.4 12.00 53.8 10.40 44.2 10.80 42.4 10.50 45.4 10.90 44.0 10.60 46.6 11.00 45.4 10.70 47.6 10.80 48.5 Acetate buffer solutions pH 3 - 6 ³ Make up the following solutions (1) 0.1M acetic acid (2) 0.1M sodium acetate (tri-hydrate) (13.6g / l) Mix in the following proportions to get the required ph ph vol. of 0.1M acetic acid vol. of 0.1M sodium acetate 3 982.3 mls 17.7 mls 4 847.0 mls 153.0 mls 5 357.0 mls 643.0 mls 6 52.2 mls 947.8 mls Phosphate buffer solutions ph 7 - 11 Make up the following solutions (1) 0.1M disodium hydrogen phosphate (14.2g / l) (2) 0.1M HCl (3) 0.1M NaOH Mix in the following proportions to get the required ph ph vol. of phosphate vol. of 0.1M HCl vol. of 0.1M NaOH 7 756.0 mls 244 mls 8 955.1 mls 44.9 mls 9 955.0 mls 45.0 mls 10 966.4 mls 33.6 11 965.3 mls 34.7
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