分析化學計算題

教授講義上的題目

有解答但是沒有過程

求解答過程及解釋. ThxA 40.0 mL sample of 0.200 M NaOCl is titrated with 0.100 M HCl. Ka for HOCl is 3.0x10-8. Calculate the pH at the following volumes:(a) V = 0 mL. (pH=10.41)(b) V = 40.0 mL. (pH=7.52)(c) V = 60.0 mL. (pH=7.04)(d) V = 80.0 mL. (pH=4.35)The drug tolbutamine (FW = 270.) has a molar absorptivity of 703 M-1cm-1 at 262 nm. One tablet of the drug is dissolved in water and diluted to a volume of 2.00 L. The absorbance of the solution at 262 nm in a 1.00 cm cell is 0.687. How many grams of tolbutamine are in the tablet? (0.528 g)
1. (a) 未加入鹽酸

溶液中僅有次氯酸根

次氯酸根會水解成次氯根及氫氧根　　　　　　OCl- H2O = HOCl OH-

Kh = Kw/Ka = 10^-14/(3x10^-8) = 3.333 x 10^-7平衡濃度：　0.2　　　　　α　　　α　　因水解而損失的次氯酸根濃度可略Kh = [HOCl][OH-]/[OCl-] = α^2/0.2 = 3.333x10^-7 =