@表山医争乾 省级精品课程申报 (1)What is the pH? (2)How many mass of HCI must be added to 25.0 mL of the buffer to change the pH by 0.07 units? 注：sodium bicarbonate-碳酸氢钠 【解】 (1) pH=pK2(H2CO:)+lg n(C0) n(HCO) 0.10mal.L×10.0mL -1032+3 000mL0g80-018rx1p0mL1014 pH+A pH=pKa2(H2CO3)+lg n(CO)-n(HCI) nHCO)+n(HCI)） 10.14-0.07=10.32+g (0.10 mol-L×1Q0mL÷60mlx25mL-HC) [(0.050mol-Lx50.0mL-0.10mol-Lx1Q0mL)+60ml25mL+(HC) 1005m400-1m).56 010 mol×100mL÷60mLx25mL-HC n(HCI)=0.044mol m(HC)=1.6g 19.Normal arterial blood has an average pH of 7.40.Phosphate ions is one of the key buffering systems in the blood.Find the buffer-component ratio of a NazHPO KH2PO4. pKH2P04=7.21 注：arterial blood-—动脉血，Phosphate ions-—磷酸盐离子 【解】 pH pK (H2PO)+ lg (HPO:) n(H,PO) 740=721+gHP02 n(H2PO) n(HPO) =107-72)=1.55 H.PO) 20、As an FDA(Food and Drug Administration食品及药物管理局)physiologist,.you need 0.600 L of formate buffer with a pH of 3.75.[pK.(HCOOH)=3.75]