chemistry

Exercise 2Significant Digits and Scientific Notation

EXERCISE 2: SIGNIFICANT DIGITS AND SCIENTIFIC NOTATION

Part 1:

Determine the number of significant digits in each number and write out the specific significant digits. Submit Part 1 and Part 2 to your professor when completed.

1. 405000

2. 0.0098

3. 39.999999

4. 13.00

5. 80,000,089

6. 55,430.00

7. 0.000033

8. 620.03080

Part 2:

Convert each number into scientific notation.

1. 70,000,000,000

2. 0.000000048

3. 67,890,000

4. 70,500

5. 450,900,800

6. 0.009045

7. 0.023

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Exercise 3 Experimental Variables

EXERCISE 3: EXPERIMENTAL VARIABLES

Identify the variables tested in each of the following experiments. If applicable, determine and identify any positive or negative controls. Submit this exercise to your instructor upon completion.

1. A study is being done to test the effects of habitat space on the survival of fish populations. Different sized aquariums are set up with six goldfish in each one. Over a period of six months, the fish are fed the same type and amount of food. The aquariums are equally maintained and cleaned throughout the experiment. The temperature of the water is kept constant. At the end of the experiment the number of surviving fish are surveyed.

a. Independent Variable:

b. Dependent Variable:

c. Controls:

2. To determine if the type of agar affects bacterial growth, a scientist cultures on four different types of agar. Five petri dishes are set up to collect results:

• One with nutrient agar and E. coli

• One with mannitol-salt agar and E. coli

• One with MacConkey agar and E. coli

• One with LB agar and E. coli

• One with nutrient agar but NO E. coli

a. Independent Variable:

b. Dependent Variable:

c. Controls:

© 2018, eScience Labs

How to download and save your Lab Safety Contract

1. To begin you will need to download this fillable PDF to your desktop by selecting the

download button in the upper right-hand corner of your browser screen.

2. Next, open the PDF in a PDF reader (ex: Adobe acrobat, Foxit, etc.) to fill out the

contract.

*** Note: If your PDF is opening in a browser page, right-click on the file to open it with a

PDF reader. If you do not have a PDF reader installed on your computer, you can download one for free online.

3. Once you have finished filling out your Lab Safety Contract, save it and submit it

to your instructor.

®

Lab Safety Contract

eScience Labs feels confident that with the knowledge of our Safety Procedures, you will be

able to create and maintain a safe laboratory experience. With your cooperation, you will be

able to eliminate, prevent, and correct possible hazards.

Please complete the questions below and, if you comply with the safety rules, sign this contract.

If you do not comply, please note this within your contract. Note that if you do not choose to

comply, you will not be included in eScience Labs’ safety and liability coverage.

Return this safety contract to your Instructor.

Questions

1. Do you wear contact lenses?

□ YES □ NO

2. Are you colorblind?

□ YES □ NO

3. Do you have any allergies?

□ YES □ NO

If YES, list specific allergies: _________________________________

4. Do the contents of your kit match the packing list?

□ YES □ NO

If NO, contact eScience labs customer support immediately to request the missing

components.

®

Student Agreement

I, _____________________ (your name) have read and choose to comply with all of the safety

rules set forth in the Safety Procedures. By signing this contract, I realize that I must obey these

rules to ensure my own safety. I will cooperate to the fullest extent with my instructor and the

protocols in my lab kit to maintain a safe lab environment. I will also closely follow any oral

and/or written instructions additionally provided by my instructor as part of a specific activity. I

am aware that any violation of this safety contract that results in unsafe conduct in the

laboratory, or misbehaviour on my part, may result in consequences as specified by my

instructor.

____________________________________

Student Signature

____________________________________

Date

____________________________________

Course Name

®

1. Do you wear contact lenses: Off
2. Are you colorblind: Off
3. Do you have any allergies: Off
4. If YES list specific allergies:
5. Do the contents of your kit match the packing list: Off
6. Course Name:
7. Student Signature:
8. Date:
9. Student Name:

How to download and save your Lab Safety Contract

1. To begin you will need to download this fillable PDF to your desktop by selecting the

download button in the upper right-hand corner of your browser screen.

2. Next, open the PDF in a PDF reader (ex: Adobe acrobat, Foxit, etc.) to fill out the

contract.

*** Note: If your PDF is opening in a browser page, right-click on the file to open it with a

PDF reader. If you do not have a PDF reader installed on your computer, you can download one for free online.

3. Once you have finished filling out your Lab Safety Contract, save it and submit it

to your instructor.

®

Lab Safety Contract

eScience Labs feels confident that with the knowledge of our Safety Procedures, you will be

able to create and maintain a safe laboratory experience. With your cooperation, you will be

able to eliminate, prevent, and correct possible hazards.

Please complete the questions below and, if you comply with the safety rules, sign this contract.

If you do not comply, please note this within your contract. Note that if you do not choose to

comply, you will not be included in eScience Labs’ safety and liability coverage.

Return this safety contract to your Instructor.

Questions

1. Do you wear contact lenses?

□ YES □ NO

2. Are you colorblind?

□ YES □ NO

3. Do you have any allergies?

□ YES □ NO

If YES, list specific allergies: _________________________________

4. Do the contents of your kit match the packing list?

□ YES □ NO

If NO, contact eScience labs customer support immediately to request the missing

components.

®

Student Agreement

I, _____________________ (your name) have read and choose to comply with all of the safety

rules set forth in the Safety Procedures. By signing this contract, I realize that I must obey these

rules to ensure my own safety. I will cooperate to the fullest extent with my instructor and the

protocols in my lab kit to maintain a safe lab environment. I will also closely follow any oral

and/or written instructions additionally provided by my instructor as part of a specific activity. I

am aware that any violation of this safety contract that results in unsafe conduct in the

laboratory, or misbehaviour on my part, may result in consequences as specified by my

instructor.

____________________________________

Student Signature

____________________________________

Date

____________________________________

Course Name

®

1. Do you wear contact lenses: Off
2. Are you colorblind: Off
3. Do you have any allergies: Off
4. If YES list specific allergies:
5. Do the contents of your kit match the packing list: Off
6. Course Name:
7. Student Signature:
8. Date:
9. Student Name:

Table of Contents + Time & Materials There may be a few additional materials required to complete your lab experiments that are not included in your eScience Labs kit. Please review the procedures and plan accordingly. Note that the times listed are approximations and may differ depending on the assignments required by your instructor and/or your previous subject knowledge.

LAB 1: INTRODUCTION TO SCIENCE

Time Required: 1 hour | Additional Materials: None

• Exercise 1: Conversion

• Exercise 2: Significant Digits

• Exercise 3: Experimental Variables

LAB 2: GENERAL CHEMISTRY LAB SAFETY

Time Required: 1 hour | Additional Materials: Camera (smartphone is fine), Pen/pencil, Distilled water, Permanent marker

• Exercise 1: Mapping Laboratory Safety

• Experiment 1: Neutralization of Acids and Bases

LAB 3: CHEMICAL NOMENCLATURE

Time Required: 1 hour | Additional Materials: None

• Experiment 1: Nomenclature Practice

LAB 4: COMPOUND FORMULAS

Time Required: 3 hours | Additional Materials: Distilled water, Oven/Toaster oven, Baking pan, Timer, Hot pad/towel, Camera (smartphone is fine), Internet access, Graphing software

• Experiment 1: Determining the Chemical Formula for Copper Gluconate

LAB 5: QUALITATIVE ANALYSIS OF IONS

Time Required: 2 hours | Additional Materials: Tap water, Permanent marker, Timer, Camera (smartphone is fine), Measuring spoons

• Experiment 1: Qualitative Analysis of Reactions

LAB 6: ELECTRON CONFIGURATION

Time Required: 1 hours | Additional Materials: None

• Experiment 1: The Chemistry of Fireworks

LAB 7: CHEMICAL BONDING

Time Required: 2 hours | Additional Materials: Scissors, Permanent marker, Paper towels, Timer, Camera (smartphone is fine), 1 g Salt

• Experiment 1: Structural Models

• Experiment 2: Melting Points and Types of Bonds

LAB 8: GAS LAWS

Time Required: 2 hours | Additional Materials: Tap water, Timer, Distilled water, Camera (smartphone is fine), Cooking pot, Stove top, Rubber band, Ice, Pencil, Internet access, Graphing software

• Experiment 1: Ideal Gas Law - Finding Percent H2O2 with Yeast • Experiment 2: Charles’ Law Part 1

• Experiment 3: Charles’ Law Part 2

LAB 9: ENTHALPY AND SPECIFIC HEAT

Time Required: 3 hours | Additional Materials: Timer, Tap water, Distilled water, Cooking pot, Stove top/microwave, Paper towels, Scissors, Toothpick, Internet access, Graphing software, Camera (smartphone is fine)

• Experiment 1: Determination of Specific Heat of a Metal

• Experiment 2: Cold Packs vs. Hand Warmers

LAB 10: ACID-BASE TITRATIONS

Time Required: 2 hours | Additional Materials: Internet access, Graphing software, Camera (smartphone is fine), Distilled water, Scissors, Permanent marker

• Experiment 1: Titrations with Taco Sauce

LAB 11: GRAVIMETRIC ANALYSIS

Time Required: 2 hours (plus 1 day for observations) | Additional Materials: Camera (smartphone is fine), Distilled water, Timer, Isopropyl alcohol

• Experiment 1: Gravimetric Analysis with Calcium Chloride and Potassium Carbonate

LAB 12: MOLAR MASS AND FREEZING POINT DEPRESSION

Time Required: 1 hours | Additional Materials: Permanent marker, Distilled water, Cubed/Crushed ice, Camera (smartphone is fine)

• Experiment 1: Determining Molar Mass from Freezing Point

LAB 13: MOLAR VOLUME OF GASES

Time Required: 1 hour | Additional Materials: Distilled water, Scissors, Camera (smartphone is fine), Permanent marker

• Experiment 1: Determining Molar Volume

LAB 14: MOLAR MASS AND VAPOR DENSITY

Time Required: 1 hour | Additional Materials: Camera (smartphone is fine), Distilled water, Paper towels, Hot pad/towel, Safety pin, Rubber band

• Experiment 1: Calculating the Molar Mass of Ethanol

Scissors, Timer, 15 g Salt, Internet access, Graphing software, Camera (smartphone is fine)

• Experiment 1: Plating Copper Gluconate

• Experiment 2: Waste Disposal of Copper Gluconate

Experiment 1Determination of Specific Heat of a Metal

Experiment Inventory

Materials 2 Styrofoam™ 8 oz. Cups

Styrofoam™ 8 oz. Cup Lid

Unknown Metal

*Camera/Smart Phone

*Stove-Top or Microwave

*Tap Water

*Wooden Toothpick (if using a microwave)

Labware 100 mL Graduated Cylinder

500 mL Glass Beaker

Test Tube Clamp

Thermometer

Scale

*Hot Pad

*Cooking Pot

*Stopwatch / Clock

*Paper TowelsNote: You must provide items listed in *red.

EXPERIMENT 1: DETERMINATION OF SPECIFIC HEAT OF A METAL

In this experiment, you will measure and record the temperature over time to determine the specific heat and identity of an unknown metal.

PROCEDURE

1. Put on your safety glasses and gloves (Provided in your safety box)

2. In a cooking pot add 500 mL of tap water, place on the stovetop and bring the water to a boil. Set a stopwatch for 3 minutes. Once it has boiled for three minutes, reduce the heat from a boil to a simmer. (See Figure 11).

Note: If you do not have a stove, heat the 500 mL of water to boiling in a microwave safe container. To avoid the risk of superheating water (water that does not look boiling, but explodes when agitated), place a microwave safe object in the water and heat the water at 1 minute increments (such as a wooden toothpick). At the end of every minute, tap the microwave safe container before removing the container from the microwave to test if your water is superheated. Superheated water can be extremely dangerous and may cause serius burns. Use extreme caution if using the microwave method to boil water. Once boiling, carefully remove the container using the provided insulated glove.

3. Using your 100mL graduated cylinder measure 50 mL of room temperature tap water into one of the Styrofoam™ cups.

Figure 11: Sample set-up for Step 1. A pot with 500 mL of water rests on a stove-top burner.

©2018, eScience Labs

4. Record the mass of the water in Table 2.

5. Put the two Styrofoam™ cups together by placing the Styrofoam™ cup containing 50 mL of room temperature tap water inside the empty Styrofoam™ cup.

6. Place your cups upright inside of the 500 mL beaker. The beaker is used to provide vertical support for the Styrofoam™ cups. (See figure 12)

7. Turn on the scale by pressing the button labeled 0/T. If your scale does not turn on, you may have to remove the battery cover and remove a small strip of plastic from the battery housing. Once the scale is on, press the 0/T button a second time to zero the scale. Make sure that the units are in grams (g). If not, press the M button until the units displayed are in grams. Pick up your unknown metal and place it on the scale. Record the weight of the unknown metal in Table 2.

8. Make sure that your metal will not protrude above the water level; if necessary you may need to carefully bend or cut it. Insert the thermometer into the hole in the lid. This apparatus is your calorimeter.

9. Put your insulated glove on over your safety glove, then pick up the unknown metal strip with the test tube clamp and hold the clamp and unknown metal in the simmering water for five minutes to ensure that the clamp and metal reach the same temperature as the water.

Hint: Do not drop the unknown metal into the pot of hot water and leave it there. It will be difficult to retrieve the heated metal from the hot water and any attempt to do so could cause severe burns.

10. After five minutes has passed, quickly transfer the hot unknown metal into the calorimeter. Remember to quickly replace the lid with the thermometer in it. Be careful to ensure that the thermometer is not touching the metal, only the water.

11. In Table 3, record the temperature of the water after five minutes has passed, every minute for five additional minutes. Gently swirl the contents of the cup right before recording the temperature.

12. Repeat Steps 1 - 10 two more times. Calculate the average heat capacity of the unknown metal. Begin by calculating q for water then use that information to calculate heat capacity for the metal.

13. Use Table 1 as a reference for determining your unknown metal.

Figure 12: Sample set-up for Step 6.

©2018, eScience Labs

Data Sheet Experiment 1 Data Sheet

Table 2: Mass

Mass (g)

Water

Unknown Metal Strip

Table 3: Specific Heat Data

Time (minutes) Temperature (°C)

Trial 1 Trial 2 Trial 3

Initial

5 minutes

6 minutes

7 minutes

8 minutes

9 minutes

10 minutes

Average Specific Heat Capacity of the Unknown Metal:

©2018, eScience Labs