Introduction

If you've ever seen the Frankenstein movies, then you are probably familiar with Hollywood's interpretation of a laboratory as a dark, dungeonesque space with a mad scientist in action. However, although lab experiences may often appear haphazard in movies, real-world scientists develop and incorporate organized protocols to keep lab environments safe. In addition to focusing on safe lab practices, the experiments in this lab manual will help you to learn about "green", environmentally-friendly chemicals and adhere to safety precautions.

Before beginning these labs, you must first realize there are specific techniques and precautions to learn to decrease the risks involved. You will need to learn the location of certain items, rules, and the names of common lab equipment. After you get acquainted with your surroundings, you will be prepared and comfortable completing the labs in this manual.

This manual is written for a "Green Chemistry" approach. This means the activities in this manual are generally safer and produce less hazardous waste than similar experiments found in other lab manuals. The chemicals used are environmentally friendly and can be discarded down a household drain with running water. Each of these experiments has been performed safely by other students. However, safer and less hazardous waste does not mean accidents, injuries, or damage will not happen. Scrapes and burns are always a possibility. These experiments will likely be performed in a household environment, so be sure a working fire extinguisher is accessible. You are advised to always use the safety glasses and gloves provided in your kit. Note that the gloves provided in your lab kit are nitrile-based, rather than latex. Please contact eScience Labs at 1-888-ESL-KITS or info@eScienceLabs.com if you require and alternate.

Safety Equipment

• Safety Glasses: Safety glasses are used to protect your eyes, and should be worn at all times when in the chemistry laboratory, even if you are not currently working with chemicals.
• Gloves: At times you may need to wear gloves to protect your hands from harmful chemicals or hot objects. The type of glove needed will depend on the application. For example, oven mitts are worn to remove hot objects from an oven while vinyl or latex gloves are used when working with acids and bases. It is very important not to
  touch your work area with gloves that have been contaminated with harmful chemicals.

  Figure 1: Using the information in this section, you will be able to complete the labs experiments in this manual safely and successfully. Can you identify what’s wrong with this picture?

• Safety Shower: A safety shower is used when a hazardous chemical is spilled on a person where they are unable to rinse it off thoroughly in the sink. It can also be used if a person’s clothes catch on fire. Most safety showers are operated by pulling a chain, although a standard home shower will also work. If a sink is insufficient to thoroughly rinse yourself, get to the nearest shower in your home as quickly as possible. This is not a time for modesty. Remove the contaminated clothing while rinsing your skin with a copious amount of water.
• Eye Wash: An eye wash is used if a harmful chemical is splashed into your eyes or face. It is usually operated by pushing forward on a handle. In the home, find the nearest sink and flush water in your eyes for at least 20 minutes. If your sink has a sprayer, use it to rinse your eyes or face while making sure the water drains into the sink.
• Fire Extinguisher: A fire extinguisher is used to put out small to medium fires.
• Laboratory Fume Hood: A laboratory fume hood removes harmful gases and fumes sometimes present when doing an experiment. You should always work in a fume hood whenever you are working with corrosive, noxious, or flammable materials. Chemicals used in this kit will not require the use of a fume hood.

Besides knowing where the safety equipment is located and how and when to use it, there are general safety rules you need to follow in the laboratory. Some of the common safety rules are listed below.

Laboratory Safety Rules

1. Always wear safety glasses. Never wear contact lenses.
2. Never attempt unauthorized experiments.
3. Always have someone available to help in the event of an accident.
4. Never have food, drink, chewing gum, or tobacco in the laboratory.
5. Always keep your work area free of clutter.
6. Always wear a protective apron and sensible clothing. This means no loose clothing, bare midriffs, or open-toe shoes.
7. Know the location of and how to use safety equipment in your home. This includes showers, fire extinguishers, and sinks.
8. Always read the experiment entirely before beginning the procedure.
9. Always wash hands before leaving the lab.
10. Tie back long hair.
11. Never run or play practical jokes in the experiment area.
12. Place broken glass in a protective container, never loosely in a trash can.

Acid-Base Behavior

In addition to following the general safety rules, chemicals need to be handled properly. In particular, two very important classes of compounds called acids and bases require special attention. These compounds are commonly used reagents in the laboratory; therefore, understanding their proper disposal is beneficial.

Physical differences between acids and bases can be detected by the some of the five senses, including taste and touch. Acids have a sour or tart taste and can produce a stinging sensation to broken skin. For example, lemon juice tastes sour. Alternatively, bases have a bitter taste and a slippery texture. Soap and many cleaning products are bases.

Acids and bases are measured on a scale called pH. pH, or potential hydrogen, is calculated using a mathematical equation that accounts for some of the chemical differences in acidic and basic compounds. This scale helps us quickly determine if a solution is very acidic, a little acidic, neutral (neither acidic nor basic), a little basic, or very basic. pH values range from less than 1 to 14. A pH of 1 is highly acidic, a pH of 14 is highly basic (or alkaline), and a pH of 7 is neutral. Table 1 lists the pH of several foods.

pH indicators, which change color under a certain pH level, can be used to determine whether a solution is acidic or basic. For example, litmus paper is made by coating a piece of paper with litmus, which changes color at around a pH of 7. Either red or blue litmus paper can be purchased depending on the experimental needs. Blue litmus paper remains blue when dipped in a base, but turns red when dipped in an acid, while red litmus paper stays red when dipped in an acid, but turns blue when in contact with a base.

Acids and bases can react with each other. In this case, the two opposites cancel each other out resulting in a product that is neither an acid nor a base. This type of reaction is called a neutralization reaction. Neutralization of an acid or base is a technique frequently used for the proper disposal of the compound. The neutralized product can usually be disposed of by flushing it down a sink.

Keep in mind that in a typical laboratory strong acids and bases, such as hydrochloric acid (HCl) and sodium hydroxide (NaOH), are commonly utilized. As mentioned previously, the experiments in this lab manual are designed with a green approach. That means that the acids and bases, in addition to the other chemicals classes, used in this manual are safe for direct disposal.

Some general guidelines for handling chemicals properly are listed below.

Handling Chemicals

1. Always add acids to water, never water to acids.
2. Never return unused chemicals to the bottles from where they were first obtained.
3. Dispose of used chemicals in the proper waste containers and/or as instructed.
4. Always clean the work area, and put away extra equipment when laboratory work is completed.
5. Never leave anything unattended while it is being heated or is reacting rapidly.
6. Never carry out a reaction or heat a substance in a closed system.
7. Always be careful when working with previously heated objects.
8. Always replace stoppers or lids on bottles containing chemicals.
9. Weigh chemicals in weigh boats or on paper provided for that purpose. Never weigh chemicals by placing them directly on the scale.
10. Label all chemicals clearly and completely.
11. Read labels carefully before using chemicals.
12. Always lubricate glass tubing or thermometers before inserting them into rubber stoppers.
13. Material Safety Data Sheets (MSDS) for all chemicals provided can be found on our website at www.esciencelabs.com/educators/msds. These sheets contain all needed information regarding the danger, safety and disposal of every chemical. Download, print, and review the MSDS for each chemical prior to using that chemical.

Even though you follow all of the safety rules, accidents can still happen. This is why it is so important to know what to do for each type of accident.

How to Respond to Accidents

1. Chemical Spills (on the Bench or Floor): Be sure to clean up the spill immediately. If the spill involves volatile or flammable materials, such as alcohol, make sure ALL flames in the lab area are extinguished and spark-producing equipment is shutdown. In the case of an acid spill, pour baking soda on the acid before cleaning up. In the case of a base spill, pour vinegar on the base before cleaning it up. All other chemicals used in this manual can be cleaned up as you normally would. If you have any questions, check the MSDS.
2. Hazardous Chemical Spills (on a Person): If the spill covers a large area, the typical course of action is to remove all contaminated clothing while the person is under the safety shower. If it is a small area, flush the area immediately with a large amount of water and then wash it with soap. Check the MSDS for the spilled chemical and follow all instructions. Medical assistance may be necessary.
3. Chemicals Spills (in the Eyes): If a harmful chemical is splashed on your face and/or in your eyes, immediate attention is critical. Call for help and get to the nearest sink. If the chemical splashes on your face, and you have glasses on, KEEP the glasses on. Remove the chemical from your face before you remove the glasses. If a chemical gets in your eyes, hold your eyes open in the eyewash for at least 20 minutes. Even though you should not be wearing contact lenses in the lab, if you are, rinse your eyes thoroughly, remove your contacts, and continue to rinse your eyes. A doctor should examine your eyes as soon as possible.
4. Chemical Ingestion: Check the MSDS immediately. Call 911 or "Poison Help" at 1-800-222-1222.
5. Burns: Flush the area with cool running water for 20 minutes. Medical attention may be necessary.
6. Cuts and Wounds: If a chemical gets into the cut or wound, rinse it off immediately with a large amount of water. Avoid contamination, and check the MSDS.
7. Fire: Fires in a laboratory are often contained in pieces of glassware, such as a beaker. You should not move a beaker that has a chemical burning in it. Instead, extinguish the fire simply by covering the mouth of the beaker with a thin curved piece of glass called a watch glass and turning off the source of the flame. A plate or pie pan can also work in place of a watch glass. If the fire is not easily covered, you can use a fire extinguisher. If the fire is too large to extinguish quickly, clear the home and call the fire department immediately.
   • Clothing fires can be extinguished in a safety shower if it is close by. If it is not very close, you will need to STOP, DROP, and ROLL to quickly smother the fire.

Additional Resources

If you have any doubt as to what you are supposed to be doing and how to do it safely:

• STOP!
• Double-check the manual
• Check the website www.esciencelabs.com
• Email: Help@esciencelabs.com
• Call for help 1-888-ESL-KITS (1-888-375-5487)
• Contact your instructor

If you have ANY questions or concerns regarding a chemical, read the MSDS for that chemical. The MSDS lists the dangers, storage requirements, exposure treatment and disposal instructions for every chemical. The MSDS for any chemical supplied by eScience Labs, LLC, can be found at www.eScienceLabs.com/educators/msds.