Uploaded by Sherry Wiles

Basic Laboratory Techniques Lab

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Basic Laboratory Techniques
Name: ___________________________________ Block: ______
Introduction
Laboratories can be very complex and a little intimidating. In this lesson, you will learn about some basic laboratory
techniques that will build your confidence by teaching you how to pour, measure, filter, and use gas burners and
glassware.
When you first set foot inside a chemistry lab, it can be a little overwhelming. There are chemicals in bottles, flame
sources, and all kinds of fragile glassware. Learning the proper techniques and how to use all the equipment can take
time, but we all must start with the basics.
Lab techniques are the processes and practices that are recommended for using various equipment in the
laboratory. In this lesson, we will go over some of the most basic lab techniques you will need to know.
Pouring and Measuring
Pouring is a technique that is used in everyday life, and spills and splatters are common. We've all seen somebody try to
pour a glass of water and make a mess all over a counter top. When it comes to pouring substances in a laboratory, the
technique must be much more precise. The basic technique to pouring liquid in a lab is using a stirring rod, or another
similar instrument. You use the stirring rod to connect the pouring spout from the source container to where you want
the liquid to go. Because liquids, especially water, are cohesive and tend to attach themselves to solid materials, using a
stirring rod allows the liquid to flow smoothly down the rod without spilling. When pouring a liquid without a stirring
rod, it is recommended to hold the two containers at arm’s length with your elbows slightly bent.
To measure the volume of a liquid using a graduated cylinder, or other calibrated and marked container, place your eye
along the level of the liquid. You will see something that resembles a bubble shape along the top of the liquid with a top
and bottom line. This is called the meniscus. The bottom of the meniscus should be lined up with the markings on the
side of the graduated cylinder for an accurate measurement.
Gas Burners and Heating
Gas burners are connected to a gas supply through rubber tubing. After the gas flow is turned on, the burner is lit with
a match or burning splint. Gas burners can be adjusted by opening or closing an air vent, which increases or decreases
the amount of air that enters the burner. The vent should be closed when the burner is first lit. This will produce a
yellow flame. As the air vent is opened, the flame will become increasingly blue, and therefore increasingly hot. It's
important to never reach over a burner, and to keep hair and loose clothing secured when using a gas burner.
When heating substances using glassware, it is important to use special, heat-resistant glassware. Also, put a piece of
wire gauze between the flame and the glass to avoid direct contact. When heating material in a test tube, the tube
should always be held using a special test tube holder or clamp, with the opening of the test tube pointed away from
everyone present.
Cleaning equipment
Once chemicals have been properly disposed of, the glass (or plastic) equipment should be washed using soap, water, and
correct sized wire brush. When soap is completely rinsed out with tap water, rinse again using distilled water. With a
constant stream of distilled water, go around the inside at the top of the equipment one to two times, swirl water
around, then pour water down the drain. Allow to air dry.
Lab
Each piece of lab equipment has a specific function and purpose. In the following experiments, you will need to use each
piece of equipment correctly. Your task is to obtain the correct lab equipment, chemicals, and supplies. You are to
follow the experiment instructions precisely and complete each experiment. Once each experiment has been completed,
properly dispose of chemicals, clean equipment, and return everything to the area you obtain it. The first few
experiments are very simple but will teach you how to use and read the equipment, so make sure you start with the first
experiment listed. The following experiments will continue to teach you how use equipment, but tend to be more
interesting. As you learn the correct procedures, you may start to notice that not every little detail is included, such as,
you may not be told to use weigh paper to weigh out chemicals. These are details and skills that is assumed. For
example, when your mom tells you to brush your teeth, you automatically know how to spit the toothpaste out of your
mouth. Also, it’s very important that you do not change the order of experiments, they build upon each other. After
each experiment, answer all questions in the lab and give as much detail as possible. Don’t forget to be careful, precise,
and wear your goggles!
Experiment 1: Accuracy of Graduated Cylinder
Materials (one of each unless specified):
Scale
100 mL beaker
100 mL graduated cylinder
Micropipette
30 Pennies
Procedure:
1. Using tap water from the sink, fill a 100 ml beaker to the 50 ml mark. Be careful, the water will spray
out of the nozzle with great force. Turn the faucet nozzle as slowly as possible to reduce splattering
water.
2. Pour the water in the 100 ml beaker into the 100 ml graduated cylinder (which is more accurate than
the beaker).
3. How accurate was your beaker measurements?
4. Add or take away water to correct the 50 ml of water in the graduated cylinder. (You may need to use
the micropipette to slowly change the water level).
5. On the electronic scale, weigh out 30 pennies and record your measurement in the table below.
6. Carefully, drop the pennies into the graduated cylinder that contains 50 ml of water. Read and record
your measurements.
7. Pour out the water to retrieve pennies. The water may be poured down the sink,
8. Complete the table by finding the density of the pennies. (D = m/v).
100 ml
Beaker and
Graduated
Cylinder
Mass of pennies
Volume of Cylinder &
pennies
Penny volume (volume of
cylinder and pennies – 50 mL)
Penny density
9. In the box below, draw a picture of a meniscus curve shown in the graduated cylinder.
10. Clean up lab space and return all equipment and materials.
Meniscus curve drawing:
Experiment 2: Pouring liquids in apparatus
Materials (one of each):
Ring stand
Utility clamp
100 mL Beaker
150 mL Beaker
50 mL Burette
Glass stirring rod
Funnel
Micropipette
Procedure:
1. Connect utility clamp to the ring stand.
2. Place an empty 150 ml beaker in the middle of the base of the ring stand where the burette will be
hanging over it.
3. Insert 50 ml burette into the utility clamp above the beaker. Make sure the bottom of the burette is
high enough so you can open and close it easily with no solution splattering out of the beaker.
4. Add 50 ml of tap water into 100 ml beaker.
5. Using the beaker only, pour approximately 15 ml of water into burette. If you over fill the burette, you
can open the spout of the burette to release the additional water. Use micropipette if
needed. Remember the meniscus curve!!
6. Using the beaker and glass stirring rod, pour approximately15 ml of water into burette. Place a third of
the glass rod into the burette. Place the lip of the beaker to the glass rod and slow pour water onto the
glass rod. If you over fill the burette, you can open the spout of the burette to release the additional
water. Use micropipette if needed.
7. Using the beaker and funnel, pour approximately 15 ml of water into burette. Place the funnel into the
burette and pour water into the funnel. If you over fill the burette, you can open the spout of the burette
to release the additional water. Use micropipette if needed.
8. Clean up lab space and return all equipment and materials. All water can be poured down the drain.
Questions:

Which was the easiest procedure for you to use and why?

If you were using corrosive solutions (solutions that will burn you if it comes in contact with your skin),
which procedure would you feel most comfortable in using?
Experiment 3: Measuring out solutions using a Erlenmeyer flask
Materials (one of each unless specified):
Erlenmeyer flask
Scale
Weigh boat
Scoopula
Glass stirring rod
100 mL graduated cylinder
Micropipette
17.5 grams of glucose
Water (for this experiment, we will use tap water but in most cases distilled water is used)
Procedure:
1. Plug in and turn scale on.
2. Place weigh boat on scale and click “tare” or “zero” button to zero out the scale.
3. Measure out 17.5 grams of glucose. Use scoopula to transfer glucose from the container to the weigh
boat.
4. Record (on line below) the exact amount of glucose measured out.
a. Weight of glucose __________________________________ (make sure you write the exact
weight shown on scale)
4. Take weigh boat with glucose and pour the glucose into an Erlenmeyer flask. Make sure you pour in
all the glucose. Don’t leave any in the boat.
5. Fill 100 ml graduated cylinder with 100 ml of tap water.
6. Using glass stirring rod, pour water into Erlenmeyer flask.
7. Swirl Erlenmeyer flask until glucose has completely dissolved.
8. Congratulations, you have now created your first solution!
9. Pour solution down the sink with plenty of water, clean up lab space, and return all equipment and
materials.
Stoichiometry (Conversion) Problem:
Figure the molarity of your solution. Fill in the blanks of the following stoichiometry problem. In General
Chemistry, you will learn how to write your own stoichiometry problem.
________ g of glucose x
________ mL of H O
2
Fill in the blanks
1 mole
x
58.8 g glucose
1000 mL = __________mole =
1 Liter
1
Liter
Calculate
1
mole
Liter
Experiment 4: Rapid Color Changing Chemistry
Materials: All liquids should be measured using graduated cylinders.
Mortar and pestle
Beakers
 1 – 100 mL
 3 – 250 mL
Graduated cylinders
 1 – 10 mL
 1- 25 mL
 1 – 100 mL
Micropipettes
Thermometer
Hot Plate
Glass stirring rod
Tongs
1000 mg Vitamin C
Iodine (2%)
Hydrogen peroxide (3%)
Liquid laundry starch
Paper towel
Procedure:
1. Place mortar and pestle on top of a paper towel.
2. Crush the 1000 mg Vitamin C tablet by placing it into the mortar and using the pestle push down and
twist on the tablet. Continue until the tablet is powder.
3. Place a 250 ml beaker of water onto a hot plate and heat between 40⁰-50° C. Maintain the temperature.
4. Liquid A: Place the Vit. C powder into a 100 ml beaker. Add 60 ml of warm water. Stir for at least 30
seconds.
5. Liquid B: Measure out 5 ml of liquid A into 250 ml beaker. Add 60 ml of warm water and 5 ml of
iodine to the beaker and mix.
6. FYI: You are now done with liquid A, you may put it aside.
7. Liquid C: In another 250 ml beaker, mix 60 ml of warm water, 15 ml of hydrogen peroxide, 2.5 ml of
liquid starch.
8. Pour all liquid B into liquid C. Then Pour the combined liquid back and forth between the two beakers
a few times. Once completed, place the beaker with the liquid down on the table and observe….be
patient.
Questions:
1. What was the exact temperature of your “warm” water?
2. When you added the iodine to the liquid A, what color did the brown iodine turn?
3. At the end of the experiment, what happened to the final liquid?
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