Introduction
Take a moment and try to envision the most beautiful thing you can think of… what do you see? For some, this thought might be of a loved one, for others this may be something in nature; a rainbow, a rainforest, an animal or even existence itself. Everyone’s perception of beauty is unique to them which makes it a highly dominant and diverse part of life. For beauty to exist life must exist and for life to exist a vital ingredient is needed… water.
Our very ability to live and experience beauty is dependent on water. Water is as critical to life as it is to the science that helps us explain it…
Task
On conclusion of this WebQuest you will have learned a diverse range of content regarding solubility, dissolution, chemical equilibrium, ions and environmental analysis techniques from chemistry modules 5 and 8. Attainment of this knowledge will then enable you to answer the following inquiry questions with great depth:
- How are the ions present in the environment identified and measured?
- Describe and analyse the processes involved in the dissolution of ionic compounds in water.
Most importantly, this WebQuest will provide you with a greater appreciation for the role water plays in both science and life.
Process
To complete this WebQuest follow the instructions provided:
1: This section will highlight the importance of water in our lives and emphasize the need to monitor and protect this dwindling natural resource in the environment.
Syllabus links:
- Module 5: Analyse the need for monitoring the environment.
- Watch the YouTube video "WATER our most precious resource" provided below.
- Create a mind map that summarizes key content from the "WATER our most precious resource" video making the central focus of the mind map about the importance of water.
- Watch the YouTube video "Protecting our water quality for people and the environment" provided below.
- Answer the following questions regarding the video content of this task:
- Identify some factors that negatively impact water quality in the environment.
- Identify some of the impacts of poor water quality for both society and the environment.
- Discuss ways that environmental water monitoring has improved your quality of living.
- Describe the importance and urgency for environmental water monitoring.
- (Optional) Answer the following challenge questions:
- Aside from monitoring water quality, what other elements in the environment are monitored during environmental monitoring?
- Briefly describe an environmental disaster that has occurred and outline the environmental monitoring that occurred following the event.
2. In nature water exists as a solution and as the previous task showed, dissolved chemicals in water affect its quality; this task explores the mechanics surrounding the solubility of compounds in water.
Syllabus links:
- Module 5: Conduct an investigation to determine solubility rules, and predict and analyse the composition of substances when two ionic solutions are mixed, for example:
- Potassium chloride and silver nitrate
- Potassium iodide and lead nitrate
- Sodium sulfate and barium nitrate
- Watch the YouTube video “Solubility and intermolecular forces | Chemistry | Khan Academy” provided below.
- Create a dot point summary of key content from the YouTube video “Solubility and intermolecular forces | Chemistry | Khan Academy”.
- Go to https://phet.colorado.edu/en/simulation/soluble-salts and download the salts and solubility simulator found on the home screen of the website.
- Using a solubility chart of your choosing, determine if the following compounds are soluble or insoluble in water and check your answers using the solubility simulator:
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- Answer the following questions regarding the content of this task:
- Define the term solution
- Identify some factors that affect the solubility of substances in water
- Describe the main properties of a compound that determine if it’s soluble or insoluble in water.
- Describe what occurs at an atomic level when a compound dissolves in water
- (Optional) Answer the following challenge questions:
- Create a simple flowchart that illustrates how a heavy metal pollutant can end up dissolved in a water source such as a lake or river; refer to solubility chemistry if possible.
- Explain why barium sulfate is used as a medical tracer referring to its solubility and other chemical properties.
3. This task expands on the content of task 2 by applying solubility charts and knowledge to the process of mixing ionic solutions together.
Syllabus links:
- Module 5: Conduct an investigation to determine solubility rules, and predict and analyse the composition of substances when two ionic solutions are mixed, for example:
- Potassium chloride and silver nitrate
- Potassium iodide and lead nitrate
- Sodium sulfate and barium nitrate
- Watch the YouTube video “Precipitation Reactions: Crash Course Chemistry #9” provided below.
- Summarise the contents of this video how you see fit.
- If the ionic solution pairs listed below are mixed, determine the product(s) of mixing them and determine if they are soluble or insoluble.
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Silver nitrate + sodium Chloride |
Iron(III) Nitrate + Sodium Hydroxide |
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Magnesium chloride + Sodium Hydroxide |
Calcium Phosphate + Sodium Chloride |
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Cobalt(II) chloride + Sodium Sulfate |
Lead(II) Sulfate + Lithium Nitrate |
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Aluminium sulfate + Barium Chloride |
Nickle(II) Nitrate + Potassium Sulfate |
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Calcium chloride + Sodium Phosphate |
Potassium Hydroxide + Calcium Chloride |
- Use the solubility simulator from task 2 to assess and self-mark your answers
- Answer the following questions regarding the content of this task:
- Define the term precipitate.
- Describe what a cation is.
- Describe what an anion is.
- Do precipitate reactions occur naturally in nature and if so, identify an example of this.
- Why are precipitation reactions in water important for the monitoring of the environment?
- (Optional) Answer the following challenge questions:
- Explain how precipitate reactions can be used when analysing dissolved ions in water solutions
- Describe are solubility rules and precipitation reactions used when treating water at desalination plants?
4. This task introduces the solubility product constant and explores deeper aspects of solubility that have been covered in previous tasks.
Syllabus links:
- Module 5: Predict the formation of a precipitate given the standard reference values for Ksp
- Module 5: Describe and analyse the processes involved in the dissolution of ionic compounds in water
- Watch the video “Introduction to solubility and solubility product constant | Chemistry | Khan Academy” provided below.
- Summarise the content of the video as you see fit
- Using the link below, go to the webpage and read the section titled “Solubility Product Constant, Ksp”
- Create a dot point summary of the contents of the webpage ensuring the questions with worked solutions on the page are included in your summary.
- Watch the video “What is Ksp? (Solubility Product Constant)” provided below.
- Summarise the process of finding Ksp from the video adding your own personal notes to the procedure to help better understand the process
5. This task covers content regarding flame tests and combines this with solubility and precipitation knowledge from tasks 2 & 3 to show how water solutions are analysed to preserve water quality and monitor the environment around us.
Syllabus links:
- Module 8: Conduct qualitative investigations using flame tests and precipitation reactions as appropriate to test for the presence in aqueous solution of the following ions:
- Cations: barium (Ba2+), calcium (Ca2+), magnesium (Mg2+), lead(II) (Pb2+), silver ion (Ag+), copper(II) (Cu2+), iron(II) (Fe2+), iron(III) (Fe3+)
- Anions: chloride (Cl–), bromide (Br–), iodide (I–), hydroxide (OH–), acetate (CH3COO–), carbonate (CO32–), sulfate (SO42–), phosphate (PO43–)
- Module 5: Conduct an investigation to determine solubility rules, and predict and analyse the composition of substances when two ionic solutions are mixed, for example:
- Potassium chloride and silver nitrate
- Potassium iodide and lead nitrate
- Sodium sulfate and barium nitrate
- Take notes of the flame test colours for the elements discussed in the video
- Watch the YouTube video “Atomic Emission Spectroscopy” provided below.
- Summarise the contents of this video with dot point summaries, flowcharts and diagrams to help with content memorisation
- Watch the YouTube video “40 FLAME TEST , PRECIPITATION TEST HSC Question” provided below.
- Copy and attempt any 15 of these questions with the assistance of your own personal internet research if required.
- (Optional) For additional challenge, attempt and complete an additional 15 of the HSC questions found in the video.
6. This task covers in depth the technique of atomic absorption spectroscopy which is used in the identification of dissolved ions in water.
- Module 8: Analyse the need for monitoring the environment
- Module 8: Conduct investigations and/or process data to determine the concentration of coloured species and/or metal ions in aqueous solution, including but not limited to, the use of:
- Colourimetry
- Ultraviolet-visible spectrophotometry
- Atomic absorption spectroscopy
- Watch the YouTube video “” provided below.
- Summarise the content of the video as you see fit using diagrams and flow charts.
- Go to weblink provided below and complete the atomic absorption worksheet by using your atomic absorption spectroscopy summary and own independent internet research as you see fit.
- (Optional) Answer the following challenge questions:
- Suggest how atomic absorption spectroscopy might be used in the monitoring of water quality in environmental monitoring.
7. This task covers the technique of gravimetric analysis, a process commonly used in environmental monitoring.
- Module 8: Conduct investigations and/or process data involving:
- Gravimetric analysis
- Precipitation titrations.
- Module 8: Analyse the need to monitor the environment
- Watch the video “Gravimetric Analysis of a Chloride Salt” provided below.
- Summarise the key features of the two videos into a single summary
- Answer the following questions regarding the content of this task:
- Identify the key features of gravimetric analysis
- Discuss the key steps that are involved in gravimetric analysis
- Explain how gravimetric analysis can be used in environmental monitoring
- Suggest reasons as to how gravimetric analysis of soil near a water source can help in the determination of the water quality of the water source
- (Optional) Summarise information from the Quizlet below into a mind map summary
https://quizlet.com/165934463/gravimetric-analysis-flash-cards/
8. This task aims to place greater emphasis on the importance of monitoring water quality in relation to heavy metal pollutants, it explores the techniques scientists use to remove them from water drawing on knowledge of precipitation reactions attained in previous tasks.
Syllabus links:
- Module 8: Analyse the need for monitoring the environment
- Module 5: Predict the formation of a precipitate given the standard reference values for Ksp
- Module 5: Derive equilibrium expressions for saturated solutions in terms of Ksp and calculate the solubility of an ionic substance from its Ksp value.
- Watch the YouTube video “Water Pollution effects and the ways to reduce it” provided below.
- Watch the video “Japan's Ominous Dancing Cats and the Disaster That Followed” provided below.
- After watching the video write down the questions from the video and attempt to complete them independently without the assistance of the video
(Note: Ignore question regarding pH in video)
- Check answers using solutions provided in the video.
- Answer the following questions regarding the content of this task:
- Construct a timeline that recounts the events surrounding the disaster at Minamata
- With reference to the disaster at Minamata, explain the importance of environmental monitoring and maintaining high water quality standards.
- Identify some ways by which heavy metal pollution can be reduced
- (Optional) Answer the following challenge questions:
- Construct a timeline that recounts the events of another heavy metal pollution disaster exclusive of the Minamata Disaster
- Construct a table that summarises a list of heavy metal pollutants and their impacts on life and the environment.
9. This task provides students with base knowledge regarding titrations then applies the obtained base knowledge to precipitation titrations which intersects with knowledge of solubility and precipitation of ion solutions.
Syllabus links:
- Module 8: Conduct investigations and/or process data involving:
- Gravimetric analysis
- Precipitation titrations
- Watch the video “Titration introduction | Chemistry | Khan Academy” provided below.
- Using the link below, go to the webpage and read the entirety of the content found there
- Create a dot point summary of the contents of the webpage ensuring the example questions with worked solutions on the page are included in your summary.
- (Optional) Answer and check answers to the practice exercises embedded throughout webpage
10. This task explores the dissolution of ions in water, a process similar to what occurs in water sources within the natural environment.
- Module 5: Describe and analyse the processes involved in the dissolution of ionic compounds in water.
- Watch the video “Dissolution and precipitation | Chemical reactions and stoichiometry | Chemistry | Khan Academy.” provided below.
- Summarise the contents of the video as you see fit using diagrams, dot points, mind maps and flow charts
- Using the link below, go to the webpage and read the section titled “The dissolution process”
- Create a dot point summary of the contents of the webpage ensuring the questions with worked solutions on the page are included in your summary.
- Read the article titled “11.1 The Dissolution Process” on the webpage provided below
https://opentextbc.ca/chemistry/chapter/11-1-the-dissolution-process/
- Answer and check answers to the end of chapter questions 1-5 found on the webpage
- (Optional) Answer and check answers to the end of chapter questions 5-8 found on the webpage
11. This task entails a wide variety of videos that link a variety of chemistry knowledge obtained with the central theme of water.
Syllabus links: - Module 5: Describe and analyse the processes involved in the dissolution of ionic compounds in water.
- Module 5: Conduct an investigation to determine solubility rules, and predict and analyse the composition of substances when two ionic solutions are mixed, for example:
- Potassium chloride and silver nitrate
- Potassium iodide and lead nitrate
- Sodium sulfate and barium nitrate
- Module 8: Analyse the need for monitoring the environment
- Module 8: Conduct qualitative investigations using flame tests and precipitation reactions as appropriate to test for the presence in aqueous solution of the following ions:
- Cations: barium (Ba2+), calcium (Ca2+), magnesium (Mg2+), lead(II) (Pb2+), silver ion (Ag+), copper(II) (Cu2+), iron(II) (Fe2+), iron(III) (Fe3+)
- Anions: chloride (Cl–), bromide (Br–), iodide (I–), hydroxide (OH–), acetate (CH3COO–), carbonate (CO32–), sulfate (SO42–), phosphate (PO43–)
- Module 8: Conduct investigations and/or process data to determine the concentration of coloured species and/or metal ions in aqueous solution, including but not limited to, the use of:
- Colourimetry
- Ultraviolet-visible spectrophotometry
- Atomic absorption spectroscopy
- Go to the quizlet “HSC solubility rules” provided below
https://quizlet.com/311510706/hsc-chemistry-solubility-rules-flash-cards/
- Answer questions and check your responses to quizlet questions
- Watch the video “CM.5.1. Water quality (HSC chemistry)” provided below.
- Summarise any new information or expansion of knowledge obtained from watching video
- Watch the video “CM.5.2. Concentration of ions in Rivers and Oceans (HSC chemistry)” provided below.
- Summarise any new information or expansion of knowledge obtained from watching video
12. This task confronts the WebQuest’s primary aim, that is be able to answer the stated inquiry questions and attain a greater appreciation of the role of water in science and life.
Syllabus links:
- Module 5: Describe and analyse the processes involved in the dissolution of ionic compounds in water.
- Module 5: Conduct an investigation to determine solubility rules, and predict and analyse the composition of substances when two ionic solutions are mixed, for example:
- Potassium chloride and silver nitrate
- Potassium iodide and lead nitrate
- Sodium sulfate and barium nitrate
- Module 5: Derive equilibrium expressions for saturated solutions in terms of Ksp and calculate the solubility of an ionic substance from its Ksp value
- Module 5: Predict the formation of a precipitate given the standard reference values for Ksp
- Module 8: Analyse the need for monitoring the environment
- Module 8: Conduct qualitative investigations using flame tests and precipitation reactions as appropriate to test for the presence in aqueous solution of the following ions:
- Cations: barium (Ba2+), calcium (Ca2+), magnesium (Mg2+), lead(II) (Pb2+), silver ion (Ag+), copper(II) (Cu2+), iron(II) (Fe2+), iron(III) (Fe3+)
- Anions: chloride (Cl–), bromide (Br–), iodide (I–), hydroxide (OH–), acetate (CH3COO–), carbonate (CO32–), sulfate (SO42–), phosphate (PO43–)
- Module 8: Conduct investigations and/or process data involving:
- Gravimetric analysis
- Precipitation titrations
- Module 8: Conduct investigations and/or process data to determine the concentration of coloured species and/or metal ions in aqueous solution, including but not limited to, the use of:
- Colourimetry
- Ultraviolet-visible spectrophotometry
- Atomic absorption spectroscopy
- Answer the following questions with assistance of summaries, questions, mind maps, diagrams and flow charts that have been accumulated from previous tasks in WebQuest; responses should refer to syllabus links where appropriate.
- How are the ions present in the environment identified and measured?
- Describe and analyse the processes involved in the dissolution of ionic compounds in water.
- Explain why water is a critical component for both life and the science that exists within it referring to the various areas of science covered within the WebQuest
- Identify any newfound knowledge you have attained from completing this WebQuest
- (Optional) As a challenge exercise, summarise all the WebQuest’s content into a single concise summary using any additional internet resources if needed to assist in the task’s completion
Evaluation
Use the marking rubric below to make a personal assessment of your understanding of content covered in this WebQuest:
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Student knowledge and understanding |
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2 |
Or…
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5
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Conclusion
Water is the our most precious resource. At any point during the WebQuest water was playing an intricate part in the science behind the concepts discussed. Water is central to life and the beauty contained within it and because of this it must be preserved, appreciated and protected. This WebQuest conveys the scientific knowledge surrounding solubility and then explores the utilisation of this knowledge in various processes in environmental monitoring, particularly with water. Hopefully a deep appreciation for science has been attained through this WebQuest journey and by now you should be able to see water beautiful world we live in…
Teacher Page
Personal account of WebQuest preparation:
Rationale:
The motivation for selecting water as the theme of the WebQuest comes firstly from the fact water has a common presence in many modules of stage 6 chemistry which created a means of linking two different chemistry modules together through this common element. As the introduction highlighted, water is essential for life to exist which makes it something that is highly relevant to any student using this WebQuest. Water on its own can be seen as boring by most so linking water to the theme of beauty not only provides a positive tone to the webquest but it provides a means of relating water the theme of water to things of beauty that students may have an interest in. Because water is such a versatile component of life it helps students to see the importance and relevance of content to various aspects of the world around them and hopefully this will foster further student interest in science.
Stage 6 HSC syllabus content covered:
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Module |
Syllabus dot point |
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5: Equilibrium and acid reactions – Solution equilibria |
- Potassium chloride and silver nitrate - Potassium iodide and lead nitrate - Sodium sulfate and barium nitrate |
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5: Equilibrium and acid reactions – Solution equilibria |
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5: Equilibrium and acid reactions – Solution equilibria |
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5: Equilibrium and acid reactions – Solution equilibria |
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8: Applying chemical ideas – analysis of inorganic substances |
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8: Applying chemical ideas – analysis of inorganic substances |
- Cations: barium (Ba2+), calcium (Ca2+), magnesium (Mg2+), lead(II) (Pb2+), silver ion (Ag+), copper(II) (Cu2+), iron(II) (Fe2+), iron(III) (Fe3+) - Anions: chloride (Cl–), bromide (Br–), iodide (I–), hydroxide (OH–), acetate (CH3COO–), carbonate (CO32–), sulfate (SO42–), phosphate (PO43–) |
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8: Applying chemical ideas – analysis of inorganic substances |
- Gravimetric analysis - Precipitation titrations |
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8: Applying chemical ideas – analysis of inorganic substances |
- Colourimetry - Ultraviolet-visible spectrophotometry - Atomic absorption spectroscopy |
Concepts students should have learned:
- How to comprehend and use a solubility chart
- The science behind solubility
- How to determine solubility by applying understanding of equilibrium constants
- How to derive equilibrium expressions using equilibrium constants
- How to predict if a precipitate will form from analysis of the equilibrium constants of solutions
- Describe and analyse the processes involved in the dissolution of ionic compounds in water
- The importance and need for environmental monitoring
- The procedure of conducting flame tests and precipitation reactions in ion identification of solutions
- The process and purpose of gravimetric analysis of solutions
- The process and purpose of precipitation titrations of solutions
- How to determine the concentration of coloured species and/or metal ions in solution by using colourimetry, ultraviolet spectrophotometry and/or atomic absorption spectroscopy
- The importance, role and relevance of water in all the above concepts that are listed