Summary

In this activity, students will use a simulation to learn about some of the sections of a safety data sheet (SDS) and how the information on SDSs can be used not only for safety purposes but also for identifying unknowns. Specifically, students will use “Section 9: Physical and Chemical Properties” to distinguish between two or three substances with similar appearances in a variety of lab-based scenarios. Particle diagrams are also included to help students visualize the substances’ behavior on a particulate level.

Grade Level

High School

NGSS Alignment

This activity will help prepare your students to meet the following standards scientific and engineering practices:

• Scientific and Engineering Practices:
  • Engaging in Argument from Evidence
  • Obtaining, Evaluating, and Communicating Information

Objectives

By the end of this activity, students should be able to:

• Use the physical and chemical properties listed on an SDS to distinguish between similar-looking substances.

Chemistry Topics

This activity supports students’ understanding of:

• Chemical and physical properties
• Lab safety

Time

Teacher Preparation: minimal
Lesson: 30-40 minutes

Materials

• Computer, tablet, or phone with internet access
• Student handout
• https://teachchemistry.org/classroom-resources/safety-data-sheets

Safety

• No specific safety precautions need to be observed for this activity.

Teacher Notes

• The simulation can be found at the following link (note that students can access the simulation without an AACT login):
  • https://teachchemistry.org/classroom-resources/safety-data-sheets
• Many students at the high school level are not familiar with SDSs and their role in maintaining a safe lab environment. This simulation introduces them to the general structure/format of an SDS and how they can be used to help identify unlabeled compounds.
• This simulation has students compare relative solubility, miscibility, melting point, and pH data to distinguish between various chemicals in lab scenarios. The student handout has them define these terms prior to interacting with the simulation, but for some students it might be helpful to have a more formal introduction or class discussion about what these terms mean if they’ve never heard them before. (See the answer key for definitions and tips on explaining.)
  • Note that the terms “miscibility” and “solubility” are similar – both describe the physical mixing of two pure substances. Solubility is more general and describes the degree to which one substance dissolves in another in a variety of combinations of states of matter (solid in liquid, gas in liquid, etc.), whereas miscibility is used specifically to describe two liquids that are mutually soluble – they can fully dissolve in one another in any ratio.
• As students may notice in the SDS sections included in this simulation, the information provided in Section 9 (and other parts of the SDS) could vary depending on the type of substance, as well as which company produced the substance and it’s SDS. This Chemistry Solutions article provides more insight into the variability between SDSs, and comparing real SDSs from different companies for the same substances could be a good discussion topic.
• Below are a few examples of the types of differences you could find:
  • Sometimes solubility is assigned numerical values at certain temperatures (ex: 317 g/L at 20°C), and other times they may just be labeled as “soluble,” “slightly soluble,” or “insoluble” – and they could also describe solubility in liquids other than water, such as alcohol or acetone, but they may not. (See note below about how solubility data is presented in this simulation.)
  • Liquids are more likely to be described as “miscible” or “immiscible” in water or other liquids (such as alcohol, glycerol, ether, etc.), whereas solids are described in terms of their “solubility.”
  • Some substances decompose before they melt and so the temperature at which thermal decomposition begins may be provided instead of a melting point.
  • Sometimes a range of pH values is given for acids or bases over a range of concentrations.
  • The SDS for materials that are liquid at room temperature may include information about vapor pressure, whereas they would not for most solids.
  • Density values may or may not be included.
• To simplify the solubility data for students who are less familiar with this concept, the data presented in this simulation either says “soluble” for substances that are soluble at a rate of more than 1 g/100 mL, or “mostly insoluble” for anything that is less soluble than that. (This is the threshold used by Flinn in their Solubility Table.) This way, students who have not learned about solubility yet won’t need to know what “slightly soluble” means and/or interpret a specific number, such as 0.017 g/L at 20°C, to draw a conclusion about the general level of solubility of the substances in the simulation.
• Students can replay scenarios and rewatch the animations as needed by selecting a scenario again from the dropdown menu or from the scenarios landing page.
• If you have not previously covered the difference between strong acids/weak acids and strong bases/weak bases, you may want to remove question 17 from the student document.
• SDSs are an important part of any chemical laboratory’s overall safety plan. ACS and AACT have many resources to help teachers maintain a safe and organized chemistry classroom, lab, and storeroom – visit the ACS Chemical Safety video collection page (with lots of related AACT resources in the sidebar) and the AACT Safety page for a videos, articles, webinars, classroom resources, and more. The list below highlights some SDS-specific resources.
• Related classroom resources from the AACT Library that may be used to further teach this topic:
  • Video: Safety Data Sheet (SDS)
  • Lesson Plan: Lab Safety and Safety Data Sheets (SDS)
  • Lesson Plan: How Modern Instrumentation Revolutionized the Poison Game
  • Activity: Dangerous Goods Specialist
  • Lesson Plan: Murder Mystery
  • Lesson Plan: Investigating Properties of Ionic and Covalent Compounds
  • Project: Chemical Disasters: Good Chemicals Gone Bad!