Chemical Information

Introduction

Chemical Information

This tutorial will demonstrate how you can use online resources to locate chemical information.

It includes chapters on:

• Identifying Chemicals
• Finding Chemical Properties
• Finding Chemical Safety Information

Introduction

Technical Requirements

To complete this module, make sure to:

• Use a desktop or laptop computer with internet access.
• Use a Firefox web browser.

How to Navigate this Tutorial

This tutorial displays in two windows.

[[throughout this tutorial, click on images for a larger view]]

The smaller window, where you are reading this text, is the Guiding Window. The Guiding Window provides directions, information, and comprehension questions about the content in the Display Window.

The larger Display Window shows live, internet resources that you will be guided through during this tutorial.

Be careful and do not exit out of tabs while completing this tutorial or you may lose your progress. We will be opening multiple tabs, but only the original Display Window tab is synced to respond to links in the Guiding Window.

Introduction

Where to begin: Accessing Chemical Information Resources

Welcome to the UNM University Libraries website (https://library.unm.edu/), currently shown in the Display Window. The University Libraries provide access to a lot of information. This can be overwhelming, so let's navigate to the Chemistry 303 Research Guide that focuses on resources relevant to the work you'll be doing in lab assignments.

From the homepage, click on the Research Guides box.

Next, search "chemistry 303". The results may show more than one result representing multiple pages on the same guide. Click on a link for "Chemistry 303".

The Display Window should show the guide's home page with a welcome message.

Chemistry 303 Research Guide (https://libguides.unm.edu/chem303) is a handy resource to refer to for your lab assignments, chemistry courses, and even your career. This Research Guide is available in your lab manual.

Introduction

The Research Guide includes four sections.

Home: Provides an overview, including contact information for the STEM Librarian.

Chemical Properties: Points to resources specifically covered in this tutorial, the MilliporeSigma Catalog and the CRC Handbook.

Safety Data Sheets: Defines Safety Data Sheets (SDS) and points to resources that contain chemical hazard information.

Tips for the Assignment: Explains CAS numbers and provides advice about determining whether a compound is liquid or solid.

Identify Chemicals

You have likely encountered chemicals with many different names or synonyms.

For example, the chemical sodium chloride might be referred to by common names like table salt, rock salt, or halite depending on its form. It is also often represented by the chemical formula NaCl.

Or perhaps you have seen that medicines have brand names like Tylenol, but also generic names like acetaminophen and a more formal chemical name N-(4-hydroxyphenyl) acetamide.

Standards for naming and identification make it easier to find and access information about chemicals.

Identify Chemicals

One way to identify unique chemicals is using Registry Numbers from the Chemical Abstracts Service (CAS).

CAS Registry Numbers are available in lots of sources, so let's look at an example. Click on this Common Chemistry link so that the Common Chemistry web resource appears in your Display Window. This resource allows you to quickly and easily confirm CAS Registry Numbers for common, everyday chemicals.

Link Help

Here you can search by chemical name or CAS Registry number.

Now, return to the Chemistry 303 Research Guide by clicking this link.

Chemical Property Information

Being able to find chemical properties can help you prepare for working with chemicals. Properties that might be of interest for work in the lab include:

• Melting or Boiling Point - Will this chemical be a liquid, solid, or gas at room temperature (20-25°C) ?
• Density - What volume of liquid chemical is needed?
• Solubility - What does a chemical dissolve in well

Two sources for common physical properties are the MilliporeSigma Catalog and CRC Handbook of Chemistry and Physics.

Chemical Property Information

MilliporeSigma Catalog (a.k.a. Sigma-Aldrich Catalog)

MilliporeSigma is a large chemical company. Their catalog offers a lot of information about the many chemicals they sell.

Click on the Chemical Properties tab in the Chemistry 303 Research Guide. The first bullet point has a link to MilliporeSigma Catalog (formerly the Sigma-Aldrich Catalog). Click on that link to navigate to the catalog, pictured below.

[[This opens a new tab in your browser. Do not exit out of any tabs.]]

Chemical Property Information

Using the search box in the upper right, search for acetylsalicylic acid.

Notice that there are several results. This is partly because chemicals often have many synonyms (e.g. aspirin, acetylsalicylic acid, 2-Acetoxybenzoic acid). Additionally, chemicals can be prepared in different ways to meet different requirements (e.g. use as medicine, use as an analytical standard).

Chemical Property Information

Making sense of results

Each search result contains the following information. We'll start with the left-most column and work our way to the right:

• The product number is on the far left (e.g. A5376).
• The next column highlights descriptive information, such as chemical standards or purity levels (e.g. ≥99.0% ).
• The next column is simply the brand label.
• The next column links to the Safety Data Sheets (SDS) -- more on this later.
• Finally, there is a pricing column.

Chemical Property Information

Since CAS Numbers are assigned to unique chemical compounds, they can be a good way to verify that you’ve found info for the correct chemical and can serve as a searching shortcut. You can find the CAS Number highlighted below. Also note the Molecular Weight (MW) is shown here for a quick reference.

Generally for your lab assignments, try to choose preparations with high purity or that are ACS certified if you have choices.

To continue the tutorial, choose the preparation “A5376 ≥99.0% (Sigma)” by clicking on the product number on the Display Window.

Chemical Property Information

Chemical Properties Information

Scroll down below the header information to the Properties information section. The melting point (mp) is listed in this section and is the temperature at which a chemical changes from solid to liquid.

The melting point is used to determine whether the chemical is liquid or solid at room temperature -- which is ~20-25°C.

• A melting point below 20-25 C is liquid.
• A melting point above 20-25 C is solid.

Click “Show More” to see additional properties. Notice that Boiling point (bp) and Density are not provided. For your lab assignments, you can enter N/A if this is the case for your chemicals.

Chemical Property Information

Safety Information

For your lab assignment, you'll be asked about chemical safety information. Scroll further down to the Safety Information section and use the Safety Data Sheet (SDS).

Detailed instructions on navigating SDS will be covered later in the Chemical Safety Hazard Information chapter of this tutorial.

Chemical Property Information

We need to return to the Chemistry 303 Research Guide, but it can be a little tricky. Notice that clicking on the above link doesn't change the Display Window because we opened MilliporeSigma in another tab that is not synced to this Guiding Window.

Switch tabs in your Display Window and click the above link again until you find the original tab synced to the Guiding Window. You should see the Chemistry 303 Research Guide in your Display Window, pictured below.

Next, we'll see an overview of another resource easily accessible from the Chemistry 303 Research Guide.

Chemical Property Information

CRC Handbook of Chemistry and Physics

This large book of tables has been printed for over 100 years and now also exists as an online database.

To navigate to the CRC Handbook from the Chemistry 303 Research Guide, click on the Chemical Properties tab. The CRC is linked in the second bullet point, CRC Handbook of Chemistry and Physics. Click on that link.

If you are off-campus, you will be asked to sign in with your UNM NetID and password to access the CRC Handbook. This sign in page will open in a new tab.

Once signed in, the CRC Handbook will open. (If you are on-campus, the CRC Handbook will open without you needing to sign in.)

Chemical Property Information

Search for acetic acid using the "Search Documents" box and make sure to click on the search button.

[[you have to click on the search button -- pressing enter doesn't work]]

In the search results, click on Physical Constants of Organic Compounds in section 3.

Chemical Property Information

Physical Constants of Organic Compounds Interactive Table

The table should show three compounds including acetic acid. Move the horizontal bar below the compounds to the right to see the information included for acetic acid:

• CAS Registry number is 64-19-7,
• Molecular Weight is 60.052 g/mol,
• Melting point is 17 ± 3°C,
• Boiling point is 117.9 ± 0.2°C, and
• Density is 1.0150 g cm-3 when measured at 20°C. Note that grams per milliliter (g/mL) is the same as grams per cubic centimeter (g cm-3). 

Chemical Property Information

Chemical Safety Hazard Information

When planning experiments and working with chemicals, it is important to know the hazards of chemicals you might encounter.

Safety Data Sheets (SDS) provide basic hazard information and are required to be made available for anyone working with chemicals.

These are one of many sources you might consult to learn about hazards and ways to protect yourself and others when working with chemicals.

Chemical Safety Hazard Information

Now, let's return to the Chemistry 303 Research Guide.

Remember, we opened the CRC Handbook in a new tab, so we need to switch back to our original tab to the left for the above link to work.

Chemical Safety Hazard Information

Let's revisit the MilliporeSigma Catalog. Like most chemical suppliers, they provides Safety Data Sheets for the chemicals they sell.

Remember that you can find this resource from the Chemistry 303 Research Guide; however, to skip the awkward multiple tab situation just click on this link: https://www.sigmaaldrich.com/united-states.html

Link Help

Search for sodium hydroxide using the search box in the upper right.

You will find many preparations of this chemical, but American Chemical Society certified preparation has product number 221465.

[[note: if you don't see this preparation at the top of the results, click "Show all results" and scroll down to get to it.]]

Once you find the the product number, click on the SDS link in order to get to the Safety Data Sheet.

Chemical Safety Hazard Information

Safety Data Sheets provide structured information in many categories. Let's take a look at some specific sections:

Section 2 provides an overview of hazards.

Scroll through to take a look at the other sections of the SDS.

Chemical Safety Hazard Information

Language in Safety Data Sheets may sometimes be technical. Below are a couple of additional sources that clearly and accessibly organize safety information.

International Chemical Safety Cards (ICSC)

See this example: ICSC 0360 - Sodium Hydroxide

Link Help

These cards present hazards and precautions in a clearly organized table.

Laboratory Chemical Safety Summaries (LCSS) available from PubChem.

See this example: Sodium Hydroxide

Link Help

These summaries provide links to citations that can be used to verify what is known about chemical hazards.

Let's wrap up by returning to the Chemistry 303 Research Guide in the Safety Data Sheets tab by clicking on this link. This is where other sources for chemical hazard information can be found.

Wrapping-up Survey

• Not Applicable: If density or boiling point data isn't available you can write "N/A".
• Hazards: Check the SDS (sect. 22 & 21, hazards statements are helpful). Summarize & write out in words.
• 2A & 2B Solubility: Write out in words, such as "Insoluble in ethanol" -- do not use abbreviations.
• Use the Chemistry 303 Research Guide: https://libguides.unm.edu/chem303

Thanks for completing this interactive tour. The goal of this tutorial is to support your work on CHEM 303 lab assignments by touring resources that contain chemical property and safety information.

Do you have feedback about this tutorial? Take a quick, three question survey to let us know what you think: https://unmulandls.az1.qualtrics.com/jfe/form/SV_81XhAnEzpdnJPVj

[[This link will open in a new tab in case you want to keep the tutorial up for reference while you work on your lab assignment.]]