[理学]201110 第四章缓冲溶液whh.ppt

碱中毒的纠正 呼吸性碱中毒 肺部呼出CO2过多　　血中H2CO3浓度过分降低 　　[HCO3-]/[H2CO3] 20/1　　血液pH ?　　　　呼吸性碱中毒 纠正：减少CO2自肺部的呼出，碱中毒即可纠正。许多情况下，可用纸口袋罩住病人口鼻，使吸入自己呼出的含较多CO2的气体，就可使碱中毒得到纠正。 代谢性碱中毒 血浆中[NaHCO3]?， 　　　　　　　　[NaHCO3]/[H2CO3] 20/1 　　血液pH 值? 　　称为代谢性碱中毒 呕吐　　胃液丢失　　脱水和碱中毒 纠正：口服稀HCl（10%） * Mixture solution of conjugate acid and conjugate base whose pH is 7. the acid-base universal indicator is added to all solution. For first and second solution, the indicator’s color are yellow, that is neutral color,. Neutral color- —yellow After the addition of 2drops of 0.1M HCl solution to the mixture solution of conjugate acid and its base, the color remains yellow. After the addition of 2drops of 0.1M NaOH solution to the mixture solution of conjugate acid and its base, the color remains yellow. The solution can resist change in pH upon the addition of small amounts of either acid or base , that is , the solution has buffer action. After the addition of 2drops of 0.1M HCl solution to the PURE WATER, the color TURNS red, indicate the solution become acid After the addition of 2drops of 0.1M NaOH solution to the PURE WATER, the color TURNS purple, indicate the solution become base * 例：用1.00 mol/LNaOH中和1.00 mol/L丙酸（用HPr代表）的方法，如何配制1000mlC总=0.1 mol/LpH=5.00的缓冲溶液（已知HPr pKa =4.87） 解：NaOH与HPr中和反应 NaOH+HPr = H2O+NaPr 1mol HPr +1mol NaOH 　　1mol NaPr C总= CHPr+CNaPr =未参加反应的CHPr+参加反应的CHPr = 0. 1 mol/L=HPr所需的总量 设需1.00 mol/LHPr总量为Xml 0.100×1000=1.00×χ χ=100ml ∵C总=CHPr+CNaPr=0.100 mol?L-1 ∴CHPr=0.100-CNaPr 代入 CNaPr CNaPr pH=pka+lg─── = pka+lg ──── CHPr 0.1-CNaPr CNaPr 5.00=4.87+lg──── 0.1-CNaPr CNaPr=0.0575mol?L-1 需生成nNaPr nNaPr= CV = 0.057×1000×10-3mol 由于1molNaOH　　　1mol NaPr nNaPr= nNaOH =CNaOH.VNaOH 0.0575×1000=1.0VNaOH V=57 . 5ml 配制方法：取1.0mol.L-1 NaOH 57.5ml与1.0mol.