16. Решение задачи по химии №001 696

1. To determine the copper content in brass, a sample of the latter q was dissolved and brought to the mark with water in a volumetric flask with a capacity of 50 ml. The solution was polarographed and the wave height was determined on the polarogram hx, mm. A standard solution of copper sulfate was prepared: an exact weight of CuSO4*5H2O weighing 9.8232 g was dissolved in 100 ml of water. To build a calibration graph, 1, 2, 3, and 4 ml of a standard solution were placed in volumetric flasks with a capacity of 50 ml and brought to the mark with water. When polarography of the obtained solutions received:
Vst, ml 1 2 3 4
hst, mm 5 15 25 35

Build a calibration graph and perform the calculation in accordance with the option:
Given:

g,g
hx, mm
ω(Cu),% Options
1 2 3
0.1000
18.0
- 0.1435
28.0
- -
23.0
58.25
Calculate ω(Cu),% m (Cu),g g ,g
Solution for all three options.

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