课件：溶解氧
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• Carefully with H2SO4
Questions
✓What is DO? ✓What are the factors affecting the
concentration of DO? • Salinity, temperature, air pressure, algae … ✓What carefulness/attention should be taken
when sampling DO sample? • Any contact with air or agitation should be
avoided, and no air bobbles are allowed.
Redox titration
Mn(II) O2 Mn(OH)4
Hd+is. Mn(IV)
• Why should the potassium iodide solution (one of the fixing solutions) be basic?
Sample handling
• One sample, parallel (two) titrations for each student.
Purposห้องสมุดไป่ตู้:
• To understand the principle of determination of dissolved oxygen,
• To master one of the volumetric methods, redox titration, as well as the sample collection and storage for the analysis of dissolved oxygen.
MnO(OH)2 (MnO2.2H2O)
I-
Mn2+ + I2 S2O32-
I- + S4O62-
Indicator: starch solution
I2 + starch I- + starch
blue colorless
Additional questions
• Describe the compound formation and color change during the titration. How does the color change?
溶解氧DO
时间安排
• 预习时，洗净DO实验所需的玻璃器皿，倒 扣晾干。每人1个溶解氧瓶。
• 星期四上午 8:15，在图书馆北面湖边的木 栈道处，采集湖水样品，每人1瓶。
• 回到实验室，集中听讲解。 • 分头做实验。 • 注意这是考试实验！
2.7. Determination of Dissolved Oxygen
Questions
✓What is DO? ✓What are the factors affecting the
concentration of DO? • Salinity, temperature, air pressure, algae … ✓What carefulness/attention should be taken
when sampling DO sample? • Any contact with air or agitation should be
avoided, and no air bobbles are allowed.
Redox titration
Mn(II) O2 Mn(OH)4
Hd+is. Mn(IV)
• Why should the potassium iodide solution (one of the fixing solutions) be basic?
Sample handling
• One sample, parallel (two) titrations for each student.
Purposห้องสมุดไป่ตู้:
• To understand the principle of determination of dissolved oxygen,
• To master one of the volumetric methods, redox titration, as well as the sample collection and storage for the analysis of dissolved oxygen.
MnO(OH)2 (MnO2.2H2O)
I-
Mn2+ + I2 S2O32-
I- + S4O62-
Indicator: starch solution
I2 + starch I- + starch
blue colorless
Additional questions
• Describe the compound formation and color change during the titration. How does the color change?
溶解氧DO
时间安排
• 预习时，洗净DO实验所需的玻璃器皿，倒 扣晾干。每人1个溶解氧瓶。
• 星期四上午 8:15，在图书馆北面湖边的木 栈道处，采集湖水样品，每人1瓶。
• 回到实验室，集中听讲解。 • 分头做实验。 • 注意这是考试实验！
2.7. Determination of Dissolved Oxygen