高一化學...功課.........

2006-10-15 5:36 am

一.計算1mol下列物質中所含氧元素質量
(1) KClO3
(2) KMnO4
(3) Ba(OH)2

二.現有0.270kg溶質的質量分數為10%的CuCl2溶液。
(1)溶液中CuCl2的物質的量是多少?
(2)溶液中Cu和Cl的物質的量各是多少?

回答 (1)

用戶160291

2006-10-15 7:31 am

✔ 最佳答案

(1) mass of 1 mol of KClO3 = (39.1+35.5+16x3) = 122.6g
mass of oxygen in it = 16x3 = 48g
% of oxygen in the compound = 48/122.6 x 100% = 39.15%
(2) mass of 1 mol of KMnO4 = (39.1+54.9+16x4) = 158g
mass of oxygen = 16x4 = 64g
% = 64/158 x 100% = 40.5%
(3) mass of 1 mol of Ba(OH)2 = 137.3+2x(16+1) = 171g
mass of oxygen = 16x2 = 32g
% = 32/171 x 100% = 18.7%

2. (1) nmass of CuCl2(aq) = 270 x 0.1 = 27g
(2) no. of moles of CuCl2 = 27 / 63.5+(35.5x2) = 0.2001... mole
mass of 0.2 mole of Cu = 0.2001... x 63.5 = 12.747...g
mass of 0.2 mole of Cl2 = 0.2001... x (35.5 x 2) = 14.252...g

參考: myself

👍 0 👎 0