Murder Mystery: A Chemical Who-dunnit'! (Katie Robinson)

Title: Using observational skills, chemistry know-how and keen intellect, students will simulate a mock dinner party and uncover a fiendish plot of sabotage.

9. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:

a. Plan and conduct a scientific investigation to test a hypothesis.

b. Evaluate the accuracy and reproducibility of data.

e. Construct appropriate graphs from data and develop quantitative statements about the relationships between variables.

NGSS

Dimension 1: Scientific and Engineering Practices

2. Developing and using models

3. Planning and carrying out investigations

4. Analyzing and interpreting data

5. Using mathematics and computational thinking

6. Constructing explanations (for science)

7. Engaging in argument from evidence

8. Obtaining, evaluating, and communicating information

Dimension 2: Cross Cutting Concepts that have Common Applications Across Fields

1. Patterns

2. Cause and effect: mechanism and explanation

4. Systems and system models

Dimension 3: Core Ideas in Four Disciplinary Areas

Student prior knowledge:

• Students should be familiar with the indicators of chemical reactions (color, heat, light, sound, gas production,odor).
• Students should be familiar with the idea that some substances look similar and therefore need chemical testing in order to distinguish between them.
• Students should be familiar with lab safety, procedures and protocols.
• Students should be familiar with taking accurate data.

Explanation:

Students are often surprised to discover how many substance look like water but are in fact completely chemically different. Therefore, it is important to expose them to substances that they may come across in their lives and teach them how to properly use these substances. It is also has boarder implications by increasing student awareness on identifying patterns in data.

The purpose of this lab is to allow students the opportunity to play detective and put their scientific observational skills to work. They will need to observe their own cups contents at well as compare that to the class as whole. Then they will need to note any changes they observe and keep accurate data. Once the lab is complete, the students will collaboratively work together using the data they collected to solve the question.

The use of the poppy seeds, rosemary oil and food dye are meant to distract students from looking for the obvious clues. They need to look at the data and back track when each person who was affected came into contact with the sodium hydroxide. This allows the students to create many hypotheses and test them out by looking at the class set of data.

Students may be already familiar with acid/base indicators or you may leave it as a mystery to be solved later in a lecture. This lab is meant to cover a broad range of science skills. It may also be used in a life science class to explain how diseases can be transmitted. Here is a link to help see the most current flu stats. (National Flu Report)

Questions & Answers:

1. How can some substances mix and not create a chemical reaction?

- There are several ways to explain this to students. First, the students can look into the idea of solutes and solvents. This allows students to understand how some substances can dissolve and create varying levels of concentration within a solution. Second, this would be a great place to talk about heat of dissolution. By explaining this, students can see that mixing chemicals will not always create an immediate change but one that can build over time. Lastly, the students can discuss the law of conservation of mass and possibly do some stiochiometry.

2. Discuss a situation in which it is necessary to identify the presence of a chemical.

- This is an important skill for a researcher to master. One instance where this would be useful would be for someone who is studying pathology. For example, a person has been admitted to the hospital with some sort of poisoning. It is the pathologists job to test the blood sample to figure out what type of poison was used. Another instance would be for a doctor to understand if two medications might react negatively if taken together. Yet another could be when a chef is trying to recreate a recipe and needs to find out what ingredients to add.

3. During this lab you had to interact with a variety of people. How can you use your lab observations and apply them to your everyday life?

- This lab is a simulation of how substances can flow through a system. In the lab, sodium hydroxide is the chemical that when the indicator is present shows how a substance can spread through a system quickly. This also can simulate how a communicable disease can spread. People interact all the time and sometimes pass on pathogens without ever showing signs.Lastly, this lab allows students to see an real world application of the scientific method as well as recognizing patterns and using data to backup claims.

Applications to Everyday Life:

Data Collection and Analysis

- Data collection is paramount when trying to support claims. Whether a person is trying to build up a preponderance of evidence, find out the answer a puzzle or even going to a murder mystery dinner party, people need the ability to look at a large body of data and try to find a correlation. It is also important for students to be able to collect accurate data. In some cases, students just need an opportunity to practice skills so they can increase the ease in which they accurately predict the outcomes based on previous experiences.

Forensic Science

- A new emerging field that many students seem to show a great amount of interest in is in the field of forensic science. With the demand on the rise, students recognize the need for a strong scientific background. In this lab, students play detective and use their ability to recognize patterns and use data to create a way to identify the origin of the chemical. Just as in the case of many forensic teams across many fields of investigation, being able to recognize chemicals based on their reaction to indicator is an important skill for students to possess.

Tracking Disease/Contamination Spread

- Just like in the movies "Ourbreak" or "Evolution", scientists are often called upon to track the progress of the spread of a certain pathogens and organisms. This happens every season with the flu and the common cold. I think this application is important because it allows students to practice how to identify movement and patterns of certain items in the natural world.

Photographs:

Please see the pictures above.

Videos:

Great for teaching about the forensic science!!!

A fun trailer to show students how important it is to track the spread of diseases.

An example to show students the reaction they can expect to see.

From the best data analyzer of all time!