Chapter 5 Chemical Reactions and Stoichiometry
Project-Based Learning - Save the Lake! A Stoichiometric Investigation
Core Mission: Students will act as environmental engineering teams to investigate the cause of a sudden fish kill in the Lake. They are tasked with analyzing data to determine that the culprit is excess fertilizer (Ammonium Nitrate, NH₄NO₃) from nearby farm runoff and calculating how much cleansing agent (Calcium Chloride, CaCl₂) is needed to precipitate the pollutant.
调查一个湖突然出现大量死鱼的原因。要求分析数据，确定罪魁祸首，来自附近农场径流中的化肥（硝酸铵，NH₄NO₃），并计算需要多少净化剂（氯化钙，CaCl₂）来沉淀污染物。
How can we use chemical reactions and stoichiometry to quantitatively diagnose and solve the water pollution crisis？
2NH₄NO₃ + CaCl₂ → 2NH₄Cl + Ca(NO₃)₂
The total mass of nitrate in the lake water (for example, 100 kg), and calculate how many kilograms of calcium chloride are needed for a complete reaction.
Inquire about the market price of calcium chloride, estimate the cost, and discuss the potential advantages and disadvantages of this plan (for example, the secondary impact of introducing calcium ions and chloride ions on water bodies).
Assessment Methods
| 评估内容 / Assessment Criteria | 描述 / Description |
|---|---|
| 工程报告 / Engineering Report | 评估内容的准确性、逻辑性、完整性和专业性。 |
| 计算过程档案 / Calculation Portfolio | 检查草稿纸上的计算步骤，确保计量学方法正确。 |
| 市政听证会表现 / Town Hall Performance | 评估沟通能力、团队合作和对知识的理解深度。 |
| 同行评价 / Peer Evaluation | 小组成员相互评价贡献度。 |
Upon completing this project, students will be able to:
Understand and write balanced chemical equations, specifically for precipitation reactions.
Master the concepts of molar mass and the mole, and perform proficient conversions between mass and moles of a substance.
Apply stoichiometry to calculate the mass of products from the mass of reactants.
Analyze real-world data to identify the limiting reactant in a reaction.
Evaluate the environmental impact of a chemical solution and create a professional recommendation report.
