physical science need it within 7 hours small lab work

Even though you are conducting these labs at home, we do want you to be aware of laboratory safety.

For this lab activity, read and answer questions in the following sections:

Read Laboratory Safety Rules and answer questions on lab report Part A: Laboratory Safety

Do not answer B, Laboratory Safety and Equipment

Answer the questions for C. Measuring Length

Complete D. Measuring the Density of a Solid: Pennies. Complete Data Table 1 and SHOW ALL WORK!

Introduction

In this introduction to the physical science laboratory, you will become acquainted with safety rules and equipment, perform a measurement of length, an experiment using density and significant figures, and use a pendulum with timer to find what determines its period.

Laboratory Safety Rules

Safety is a very important issue in any laboratory. All students are required to follow the laboratory rules listed. Violation of the rules may result in a student being removed from the laboratory for the one lab period. Continual violation of the rules will be grounds for action aimed at removing the vio­ lator from the laboratory on a permanent basis

1. Approved safety goggles are required to be worn at all times for experiments involving chemicals. Persons with contact lenses are encouraged to wear glasses to the lab, if possible. Students wearing eyeglasses or contacts must wear safety goggles also. Approved safety goggles are available at Phillips Bookstore.

2. Eating and drinking in the laboratory are absolutely forbidden. Any food or beverage brought into the laboratory will be considered contaminated and will be disposed of immediately.

3. Backpacks, purses, books, and jackets may not be placed on or around a lab bench, or on the floor. They can cause spills or present a tripping hazard. All belongings must be stored in an area designated by the lab instructor.

4. No horseplay, roughhousing, or any other form of physical activity not directly required for the experiments will be tolerated in the laboratory.

5. Students must have supervision while in the lab. Students are not permitted in the laboratory without a lab instructor present.

6. No unauthorized experiments of any kind will be performed by any student.

7. No open-toed shoes, flip-flops, or sandals are to be worn in the laboratory.

8. Shorts, skirts, and dresses must be knee-length or longer. All students are reminded that chemicals have a tendency to spill and stain clothes. Students are encouraged to wear old clothes to the lab.

9. No exposed midriffs (stomach area) will be permitted.

10. Long hair (shoulder length or longer) should be tied back so that it does not hang over open flames or in the student's face. This rule applies to both genders.

11. Know the location of all safety equipment, including exits, safety showers and eyewashes, fire extinguishers, and fire alarms.

12. All accidents involving personal injury, no matter how minor, must be reported to the teaching assistant, supervisor, or to the instructor immediately.

13. Wash skin thoroughly in the event of contact with hazardous chemicals. All accidents involving spilled chemicals or broken glass, no matter how minor, must be reported to the teaching

assistant, supervisor, or to the instructor immediately.

14. The laboratory work area must be kept clean at all times.

Laboratory Equipment

Common laboratory equipment is illustrated on page vii of your laboratory manual. You will locate these items on the cart in the laboratory and draw a sketch of the equipment listed on your data sheet.

Measuring Length

You will draw a line 12.7 cm long on your report sheet and answer questions about its length.

Measuring the Density of a Solid: Pennies

In this experiment, you will determine the density of United States pennies. Pennies are made of cop­ per, but are they pure copper? You will compare the density value you obtain for pennies to the known density value of copper, which is 8.96 g/mL.

To determine if the pennies are pure copper (using density), you will need to determine both the mass

and volume of the pennies, given the density equation:

Density = mass/ volume (units of g/mL, or kg/L))

Equipment

Pennies (minted after 1983) 50 mL graduated cylinder Top loader balance

Data is provided for you in Data Table 1.

Procedure

You will use the electronic balance at your desk. Lift the lid open and press the ON/OFF button. After a few seconds the screen will read "0.00 g". If it does not, press the ZERO button to TARE the balance before weighing.

1. Count out 20 pennies and weigh them together on the balance. If the pennies are wet, dry them first with a paper towel.

2. Record the mass of the pennies to the nearest 0.01 g on the data table. You now have the mass

component of the density equation.

3. Determine the volume of the pennies using a method of "water displacement." Add between 20 and 30 mL water to a graduated cylinder. Record this initial volume to the nearest 0.1 mL on your data sheet. You will need to estimate between the lines on your graduated cylinder. Ask your instructor if you need help.

4. Carefully place all 20 pennies into the water in the graduated cylinder. The water level will rise, or be displaced, by an amount equal to the volume of the pennies. Read and record the new, or final volume, to the nearest 0.1 mL. The difference between the final and initial water volumes is equal to the volume the pennies occupy. Calculate this volume on the data sheet.

5. Calculate the density of the pennies on your data sheet. Make sure that you use the correct sig­ nificant figures in your calculation. (See page ix)

6. Perform a second trial by repeating steps 1 to 4. Use a different initial volume of water.

7. Calculate the average of both density trials, and be sure to use correct significant figures.

NAME. PARTNER, SECTION _

Data and Results for Safety and Measurement

A. Laboratory Safety

1. Why must goggles be worn at all times in the chemistry laboratory? Please use complete sentences throughout your work.

2. Where should backpacks, purses, books, jackets, etc. be placed in the laboratory? Why can they not be at or around your bench?

3. What should you do in case of a chemical spill or injury that occurs while in the lab?

4. What types of shoes and clothing are not permitted to be worn in the lab?

5. Why are food and drink not allowed in the laboratory?

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6 Experiments in Physical Science

B. Laboratory Safety and Equipment = DO NOT DO THIS SECTION

1. In the table below, give the location of five safety features found in this laboratory.

Safety Feature	Location

2. Draw the following items in the space below.

a. Erlenmeyer flask b. Graduated cylinder c. Pasteur pipette

C. Measuring Length Do this section.

In the space below, use a small ruler to draw a straight line measuring 12.7 cm.

What is its length in millimeters? (always include units.) _ In meters? _

In kilometers?

NAME PARTNER. SECTION _

D. Measuring the Density of a Solid: Pennies

DATA TABLE I

Trial I

Trial 2

Mass of pennies using balance

50.03 g

50.18 g

Density = volume =

mass

Average both density calculations (show your work):

Average penny density: _

Initial volume of water in cylinder	50.0 ml	58.3 ml
Final volume of water plus pennies	57.0 ml	65.1 ml
Volume of pennies (Final - Initial)	7.0 ml	6.8 ml
Density of pennies: (show your work below)	g/ml	g/ml

3. The density of pure copper is 8.96 g/mL. Are U.S. pennies made of pure copper? Explain your answer.

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