general field of study, and provides a very basic introduction to chemistry. The scientific method

EXERCISE 1

Introduction to Lab Science, Measurement, and Chemistry

INTRODUCTION

This lab introduces the student to the fields of anatomy and physiology, discusses science as a general field of study, and provides a very basic introduction to chemistry. The "scientific method" is a description of a broad number of procedures and experimental techniques. The goals of valid science have criteria of experimental repeatability and prior publication rights that are followed by members of the scientific community.Terms such as hypothesis , control group, experimental group, theory, and law can help students distinguish the specific parameters of scientific study from what is commonly perceived as science by the layperson. Another important area for discussion is the topic of honesty in science. Recent court cases involving interpretation of data by "paid consultants" has blurred the objectivity of the scientific experience, yet good discussions can be had by opening-up the topics of honesty in the commercial development of new drugs and the need for honest appraisal of one's work when the efforts of science are used for purposes that concern the health or well-being of people.Another part of the lab introduces the student to the idea of data collection, working with data, graphing results, and interpreting the data in a very simple format. Some students will have no difficulty with the numerical portion of the exercise while others may feel very frustrated. It is a good time to make an early evaluation of students' proficiency in math and the potential need for math review. Some anatomy and physiology courses have chemistry as a prerequisite and some do not. This lab exercise involves some basic and fundamental concepts of chemistry but is not meant to cover even the essentials of chemistry needed for the course. A good reference source for chemistry is important for those students who have had no chemistry background.TIME 1.5-2 hours

MATERIALS

Acid/Base Five 10 mL test tubes and test tube racks Safety goggles and gloves 10 mL graduated cylinder Permanent marker Distilled water in dropper bottle 0.1 M HCl in dropper bottle 0.1 M NaOH in dropper bottle Baking soda (sodium bicarbonate) Sodium chloride (table salt) Wide-ranging pH paper (pH 1–14) Parafilm ®

Small metal spatula Balance and weigh paper 1 Anatomy & Physiology The Unity of Form and Function 7e Kenneth Saladin ( Solutions Manual All Chapters, 100% Original Verified, A+ Grade) All Cha pters Solutions Manual Supplement files download link at the end of this file. 1 / 4

Ionic and Covalent Molecules 18 gauge wire Alligator clips

• volt battery
• volt flashlight bulb

Miniature screw lamp receptacle (Carolina #756481 or Sargent Welch #CP 33008-00) Two 50 mL beakers 15% sucrose solution in dropper bottle 15% sodium chloride solution in dropper bottle

Hydrogen Bonds Graduated cylinder Two 50 mL beakers Small bottle of distilled water Small bottle of ethanol (70% or greater) Hot plate (do not use open flame)

Heart Rate and Exercise Clock or watch with accuracy in seconds Calculator

REVIEW ANSWERS

• The scientific discipline that studies the function of the human body is known as:

Ans: physiology

• In terms of base units
• What is the base unit of length in the metric system?

Ans: the meter

• What is the base unit of volume in the metric system?

Ans: the liter

• How many cubic centimeters are there in 200 milliliters?

Ans: Cubic centimeters and milliliters are interchangeable, therefore there are 200 cubic centimeters in 200 mL.

• Assume a pill has a dosage of 350 mg of medication. How much medication is this in grams?

Ans: There are 1,000 mg in one gram so there would be 0.35 grams of medication in 350 mg.

• How would you write 0.000345 liter in scientific notation?

Ans: 3.45 X 10

-4 liters

• How many milligrams are there in 4.5 kilograms?

Ans: 4,500,000 milligrams

• How many meters is 250 millimeters?

Ans: 0.25 meters

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• If given a length of 1/10,000 of a meter

a. Convert this number into a decimal:

Ans: 0.0001

b. Convert it into scientific notation:

Ans: 1 X 10

• 4

• Use a word to describe

a. one-thousandth of a second:

Ans: millisecond

b. one-thousand liters:

Ans: kiloliter

c. one-hundredth of a meter:

Ans: centimeter

• Did you see a trend in your results with heart rate and exercise? If so, what do you predict for

additional exercise? Would the trend continue indefinitely? Why or why not?Ans: D etermined by experimentation. Heart rate should increase with exercise until the maximum heart rate is achieved. After that time the rate should stay the same even with an increase in energy expended.

• In terms of heart rate and exercise, which one is the dependent variable and which one is the

independent variable?Ans: E xercise is the independent variable and heart rate is the dependent variable.

• According to your bar chart (chart 2), what would be the mean heart rate at 150 seconds of

exercise?

Ans: determined by experimentation

• Define the term buffer.

Ans: A chemical that dampens the change in pH when acid or base is added to solution.

• a. In the pH experiment (step 3), when you added 10 drops of HCL, the pH changed by how

much?

Ans: determined by experimentation. It should have decreased.

• How did the addition of buffer (steps 4 and 5) prior to adding 10 drops of HCl alter the pH.

Ans: determined by experimentation, but it should be less than what occurred in 14a

• What is the neutral pH?

Ans: 7

• Is a pH of 8 more basic or less basic than a pH of 6?

Ans: A pH of 8 is more basic than a pH of 6.

• As a solution becomes more acidic what happens to the concentration of hydrogen ions?

Ans: The hydrogen ion concentration increases.

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• The term electrolyte is derived from the words electro (“electricity”) and lyte (“to separate”).

How does this term correlate with your experiment?Ans: Solutions with more electrolytes conduct electricity better than those of pure water.

• In which bond are electrons significantly shared between atoms?

Ans: c ovalent bonds

• Which bond—covalent, ionic, or hydrogen—is a weak bond? Ans: Hydrogen bonds are weak

bonds.

CHAPTER SUMMARY DATA

• 1 centigram
• 1 kilosecond
• 1 decameter
• 1 nanoliter
• 4.3 x 10

6

• 3.4 x 10

-5

• 2.2 x 10

3

• 1.9 x 10

-3

• Exercise is the independent variable and heart rate is the dependent variable. As exercise increases

so does heart rate.10-17. Results will vary depending on data collected in class.

• The solution with sodium chloride has solute particles composed of ions.
• The solution with sugar has solute particles with covalent bonds.

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