that the times listed are approximations and may differ

General ChemistryStudent ManualTable of ContentsIntroductionLab 1 Introduction to ScienceLab 2 General Chemistry Lab SafetyAdvancedLab 3 Nuclear ChemistryLab 4 Reaction RatesLab 5 Equilibrium ConstantsLab 6 Preparation of Buffer SolutionsLab 7 Standardization of a SolutionLab 8 Titration IndicatorsLab 9 Oxidation-Reduction ReactionsLab 10 Separation by ChromatographyLab 11 Electrochemical SeriesLab 12 Electrochemical CellsLab 13 Organic CompoundsLab 14 Coordination Compounds and IsomersAppendix::Good Lab TechniquesPeriodic Table3Time and MaterialsIf you are allergic to nitrile, please contact us and we will send you alternative gloves.Please note that the times listed are approximations and may differ. Please readthrough the procedure and plan accordingly.Lab 1Introduction to ScienceTime Required: 1 hour plus 7 – 10 days for observationAdditional Materials: Warm waterLab 2General Chemistry Lab SafetyTime Required: 30 minutesAdditional Materials: NoneLab 3Nuclear ChemistryTime Required: 30 minutesAdditional Materials: NoneLab 4 Reaction RatesTime Required: 1 hourAdditional Materials: Graphing software program, computer, and distilled waterLab 5 Equilibrium ConstantsTime Required: 45 minutesAdditional Materials: Distilled waterLab 6 Preparation of Buffer SolutionsTime Required: 1 hourAdditional Materials: Distilled water5Time and MaterialsLab 7 Standardization of a SolutionTime Required: 1 hour 30 minutesAdditional Materials: Distilled waterLab 8 Titration IndicatorsTime Required: 1 hourAdditional Materials: Distilled waterLab 9 Oxidation-Reduction ReactionsTime Required: 1 hourAdditional Materials: Stove top or hot water bathLab 10 Separation by ChromatographyTime Required: 2 hoursAdditional Materials: Isopropyl alcohol, distilled water, and household items to create two unique eluting solventsLab 11 Electrochemical SeriesTime Required: 1 hourAdditional Materials: Scissors, distilled water, and isopropyl alcoholLab 12 Electrochemical CellsTime Required: 1 hourAdditional Materials: ScissorsLab 13 Organic CompoundsTime Required: 1 hourAdditional Materials: Distilled water6Time and MaterialsLab 14 Coordination Compounds and IsomersTime Required: 30 minutesAdditional Materials: None7Safety InformationeScience Labs, LLC designs every kit with safety as a top priority. Nonetheless, these are sciencekits and contain items which must be handled with care.Safety in the laboratory always comes first!Lab SafetyAlways follow the instructions in your laboratory manual and these general rules:Lab Preparation•Please thoroughly read the lab exercise before starting!•If you have any doubt as to what you are supposed to be doing and how to do it safely,please STOP and then:!!Check www.esciencelabs.com for updates and tips.!•Double-check the manual instructions.Contact us for technical support by phone at 1-888-ESL-Kits (1-888-375-5487) or byemail at Help@esciencelabs.comRead and understand all labels on chemicals.!•If you have any questions or concerns, refer to the Material Safely Data Sheets (MSDS)available at www.esciencelabs.com. The MSDS lists the dangers, storage requirements, exposure treatment and disposal instructions for each chemical.Consult your physician if you are pregnant, allergic to chemicals, or have other medical conditions that may require additional protective measures.Proper Lab Attire•Remove all loose clothing (jackets, sweatshirts, etc.) and always wear closed-toe shoes.•Long hair should be pulled back and secured and all jewelry (rings, watches, necklaces,earrings, bracelets, etc.) should be removed.•Safety glasses or goggles should be worn at all times. In addition, wearing soft contactlenses while conducting experiments is discouraged, as they can absorb potentially harmfulchemicals.•When handling chemicals, always wear the protective goggles, gloves, and the apron provided.9Safety InformationPerforming the ExperimentDo not eat, drink, chew gum, apply cosmetics or smoke while conducting an experiment.•Work in a well ventilated area and monitor experiments at all times, unless instructed otherwise.•When working with chemicals:!Never return unused chemicals to their original container or place chemicals in an unmarked container.!Always put lids back onto chemicals immediately after use.!Never ingest chemicals. If this occurs, seek immediate help.Call 911 or “Poison Control” 1-800-222-1222•Never pipette anything by mouth.•Never leave a heat source unattended.!If there is a fire, evacuate the room immediately and dial 911.Lab Clean-up and Disposal•If a spill occurs, consult the MSDS to determine how to clean it up.•Never pick up broken glassware with your hands. Use a broom and a dustpan and discard ina safe area.•Do not use any part of the lab kit as a container for food.•Safely dispose of chemicals. If there are any special requirements for disposal, it will be noted in the lab manual.•When finished, wash hands, lab equipment, and work area thoroughly with soap and water.Above all, read the manual carefully and pay close attention to the safetyconcerns prior to starting an experiment.10Student PortalAll labs include supplemental lab drills and introductory concept animations. Inaddition to the learning activities listed below.Introduction:ESL Safety VideoESL Scientific Method VideoChemistry MathUnit ConversionsSample Labware ImageMatter and Structure:Chemical Reactions and StoichiometryChemical FormulasPrecipitation ReactionsDouble Replacement ReactionsThe Structure of an AtomAtomic Symbols, Atomic Numbers, and Mass NumbersChemical Bonding:Intermolecular ForcesIonsLog on to the Student Portalusing these easy steps:Visit our website,www.esciencelabs.com, and clickon the green button (says“Register or Login”) on the topright side of the page. Fromhere, you will be taken to a loginpage. If you are registering yourkit code for the first time, clickthe “create and account” hyperlink. Locate the kit-code, locatedon a label on the inside of the kitbox lid. Enter this, along with other requested information into theonline form to create your useraccount. Be sure to keep track ofyour username and password asthis is how you will enter the Student Portal for future visits. Thisestablishes your account with theeScience Labs’ Student Portal.Have fun!Ion ChargesCovalent BondsAtomic Structure and Ionic BondingChemical Bonds11Student PortalGas Laws and Enthalpy:Ideal Gas LawsGas Volume and Molar AmountMolarityGas Laws and Enthalpy (continued):EnthalpyEnthalpy and Melting IceTitrations, Indicators, and Standard Solutions:Acid-Base SolutionsAcid-Base ReactionspH ScaleMolar Quantitation:Conversion Between Mass and MolesModeling Relative Atomic MassThe Three States of MatterEffect of Temperature on the Vapor Pressure of a LiquidPhase DiagramsGas PropertiesCalculating Gas Density from Standard Molar VolumeNuclear Decay and Reaction Rates:CatalystsReactions and Rates12Student PortalAcid-Base Equilibria**Lab Drills and Introductory Animations Only**Redox Reactions and Electrochemical ActivityOxidation-Reduction ReactionsCommon Types of Oxidation-Reduction ReactionsBalancing Oxidation-Reduction ReactionsSeparation by ChromatographyMolecule PolarityPaper ChromatographyElectrochemical CellsConductivityPolarityCompounds and Isomers:Build a MoleculeBiomolecules: LipidsShapes of Simple MoleculesShapes of Simple Molecules (Part 2)13Sample Labware15Before You Start…Isopropyl AlcoholIsopropyl alcohol is required as a chemical ingredient in many of the experiments in this lab manual. Due toshipping restrictions on isopropyl alcohol (set forth by the U.S. Department of Transportation) you will needto purchase one bottle of isopropyl alcohol (rubbing alcohol) prior to starting the lab experiments.Isopropyl alcohol can typically be purchased at a grocery or drug store. You will need approximately 260 mLto complete the full set of lab experiments. This will cost approximately $2.As a reminder, alcohol bottles should always be placed away from open flames.Sodium HydroxideAdditional shipping requirements limit the volume of sodium hydroxide that can be shipped to 30 mL. The fullset of experiments in this lab manual requires 55 mL of 0.1 M sodium hydroxide. Your kit includes 30 mL of0.2 M sodium hydroxide. Therefore, you must dilute the chemical with 30 mL of distilled water. To safely perform accomplish this:1. Put on safety glasses and gloves (provided in the safety box).2. Measure 30 mL of distilled water using the 100 mL graduated cylinder (provided in yourkit).3. Pour the water directly into the chemical bottle labeled “30 mL 0.2 M Sodium Hydroxide,NaOH”. Be careful to avoid any splash-back.4. Use a permanent marker to cross out the “0.2 M” portion of the label and write “0.1 M” instead.The chemical bottle can hold 60 mL of liquid. You do not need to transfer to liquid to a new bottle.Distilled WaterIn addition to isopropyl alcohol, there is also a large amount of distilled water required for your experiments.The high volume required makes it necessary for you to purchase your own bottle of distilled water.Please make this purchase prior to beginning your labs to ensure that you are prepared at all times. You willneed approximately 1600 mL to complete the full set of lab experiments. A gallon of distilled water containsapproximately 3785 mL, and will provide more than enough water to complete your labs. Distilled water canbe purchased at any grocery store for approximately $1.MSDSThe MSDS for every chemical in this kit is provided at www.esciencelabs.com/educators/msds. eScience17Before You Start…Labs highly recommends that you download and print all of the MSDS prior to starting your experiments. Bydoing so, you will ensure that you have all of the safety and cleanup information you need should you spill orencounter an accident during an experiment.If you have questions about any of this information, please email eScience Labs at info@esciencelabs.comor call 888-ESL-KITS.Green ChemistryGreen chemistry is division of chemistry which focuses on sustainable, high-quality, and environmentallyfriendly experimental techniques. It proposes alternative procedures and materials which minimize the chemical impact on human health, reduce risk in the laboratory, and aims to eliminate the potential for environmental contamination. Green chemistry is becoming more and more common throughout chemistry. Familiarity of the tenets of this philosophy will help you perform experiments, as well as answer post-lab and realworld questions. The primary tenets are:••••••••Minimize or prevent waste whenever possible.Use catalysts rather than stoichiometric quantities to avoid using unnecessary chemical amounts.Avoid using chemical derivatives to decrease total waste created.Ensure efficient chemical processes.Use eco-friendly, biodegradable chemicals when possible.Prepare for an experiment by collecting needed analytical tools prior to beginning the experiment.This reduces the possibility for hazardous waste development.Integrate recycled or upcycled materials whenever possible.Implement energy-efficient laboratory tools.eScience Labs supports the green chemistry philosophy by integrating it into the core of all experimental procedures included in the manual. In doing so, students and teachers are offered a safe, reliable, and sustainable avenue for chemistry education. Additional green chemistry information is available online atwww.epa.gov/greenchemistry/Fire HazardsSeveral of the experiments require use of a Sterno® or flame to create the desired chemical reaction. Pleasebe extra careful when working with flames to prevent burning yourself, lab-ware, or chemicals. Plastic labware should never be used when working with flames!Thank you,The eScience Labs Team18IntroductionLab 1Introduction to ScienceIntroduction to ScienceConcepts to Explore•The Scientific Method•Controls•Observations•Data Analysis•Variables•CalculationsIntroductionWhat is science? You have likely taken several classes throughout your career as a student, and know that itis more than just chapters in a book. Science is a process. It uses evidence to understand the history of thenatural world and how it works. Scientific knowledge is constantly evolving as we understand more about thenatural world. Science begins with observations that can be measured in some way, and often concludes withobservations from analyzed data.Following the scientific method helps to minimize bias when testing a theory. It helps scientists collect andorganize information in a useful way so that patterns and data can be analyzed in a meaningful way. As a scientist, you should use the scientific method as you conduct the experiments throughout this manual.Figure 1: The scientific method process.21Introduction to ScienceThe process of the scientific method begins with an observation. For example, suppose you observe aplant growing towards a window. This observation could be the first step in designing an experiment. Remember that observations are used to begin the scientific method, but they may also be used to help analyze data.Observations can be quantitative (measurable), or qualitative (immeasurable; observational). Quantitativeobservations allow us to record findings as data, and leave little room for subjective error. Qualitative observations cannot be measured. They rely on sensory perceptions. The nature of these observations makesthem more subjective and susceptible to human error.Let’s review this with an example. Suppose you have a handful of pennies. You can make quantitative observations that there are 15 pennies, and each is 1.9 cm in diameter. Both the quantity, and the diameter,can be precisely measured. You can also make qualitative observations that they are brown, shiny, orsmooth. The color and texture are not numerically measured, and may vary based on the individual’s perception or background.Quantitative observations are generally preferred in science because they involve "hard" data. Because ofthis, many scientific instruments, such as microscopes and scales, have been developed to alleviate theneed for qualitative observations. Rather than observing that an object is large, we can now identify specificmass, shapes, structures, etc.There are still many situations, as you will encounter throughout this lab manual, in which qualitative observations provide useful data. Noticing the color change of a leaf or the change in smell of a compound, forexample, are important observations and can provide a great deal of practical information.Once an observation has been made, the next step is to develop ahypothesis. A hypothesis is a statement describing what the scientistthinks will happen in the experiment. A hypothesis is a proposed explanation for an event based on observation(s). A null hypothesis is atestable statement that if proven true, means the hypothesis was incorrect. Both a hypothesis and a null hypothesis statement must betestable, but only one can be true. Hypotheses are typically written inan if/then format. For example:Hypothesis:If plants are grown in soil with added nutrients, then they willgrow faster than plants grown without added nutrients.Figure 2: What affects plant growth?22Introduction to ScienceNull hypothesis:If plants are grown in soil with added nutrients, thenthey will grow at the same rate as plants grown insoil without nutrients.If plants grow quicker when nutrients are added, then the hypothesis is accepted and thenull hypothesis is rejected.There are often many ways to test a hypothesis. However, three rules must always be followed for results tobe valid.•The experiment must be replicable.•Only test one variable at a time.•Always include a control.Experiments must be replicable to create valid theories. In other words, an experiment must provide precise results over multiple trials Precise results are thosewhich have very similar values (e.g., 85, 86, and 86.5) over multiple trials. By contrast, accurate results are those which demonstrate what you expected to happen(e.g., you expect the test results of three students tests to be 80%, 67%, and100%). The following example demonstrates the significance of experimental repeatability. Suppose you conduct an experiment and conclude that ice melts in 30 seconds when placed on a burnPrecise results may noter, but you do not record your procedure or define the pre- hit the bulls-eye, but theycise variables included. The conclusion that you draw will all hit the same region.not be recognized in the scientific community becauseother scientists cannot repeat your experiment and find the same results. What if another scientist tries to repeat your ice experiment, but does not turn on the burner; or,uses a larger ice chunk. The results will not be the same, because the experimentAccurate results all hit was not repeated using the same procedure. This makes the results invalid, andthe bulls-eye on a target. demonstrates why it is important for an experiment to be replicable.Variables are defined, measurable components of an experiment. Controlling variables in an experiment allows the scientist to quantify changes that occur. This allows for focused results to be measured; and, for refined conclusions to be drawn. There are two types of variables, independent variables and dependent variables.Independent variables are variables that scientists select to change. For example, the time of day, amountof substrate, etc. Independent variables are used by scientists to test hypotheses. There can only be one independent variable in each experiment. This is because if a change occurs, scientists need to be able to pinpoint the cause of the change. Independent variables are always placed on the x-axis of a chart or graph.23Introduction to ScienceDependent variables are variables that scientists observe in relationship to the independent variable. Common examples of this are rate of reaction, color change, etc. Any changes observed in the dependent variable are caused by the changes in the independent variable. In other words, they depend on the independentvariable. There can be more than one dependent variable in an experiment. Dependent variables are placedon the y-axis of a chart or graph.A control is a sample of data collected in an experiment that is not exposed to the independent variable.The control sample reflects the factors that could influence the results of the experiment, but do not reflectthe planned changes that might result from manipulating the independent variable. Controls must be identified to eliminate compounding changes that could influence results. Often, the hardest part of designing anexperiment is determining how to isolate the independent variable and control all other possible variables.Scientists must be careful not to eliminate or create a factor that could skew the results. For this reason, taking notes to account for unidentified variables is important. This might include factors such as temperature,humidity, time of day, or other environmental conditions that may impact results.There are two types of controls, positive and negative. Negative controls are data samples in which youexpect no change to occur. They help scientists determine that the experimental results are due to the independent variable, rather than an unidentified or unaccounted variable. For example, suppose you need toculture bacteria and want to include a negative control. You could create this by streaking a sterile loopacross an agar plate. Sterile loops should not create any microbial growth; therefore, you expect no changeto occur on the agar plate. If no growth occurs, you can assume the equipment used was sterile. However, ifmicrobial growth does occur, you must assume that the equipment was contaminated prior to the experimentand must redo the experiment with new materials.Alternatively, positive controls are data samples in which you do expect a change. Let’s return to thegrowth example, but now you need to create a positive control. To do this, you now use a loop to streak aplate with a sample that you know grows well on agar (such as E. coli). If the bacteria grow, you can assumethat the bacteria sample and agar are both suitable for the experiment. However, if the bacteria do not grow,you must assume that the agar or bacteria has been compromised and you must re-do the experiment withnew materials.The scientific method also requires data collection. This may reflect what occurred before, during, or afteran experiment. Collected data help reveal experimental results. Data should include all relevant observations, both quantitative and qualitative.After results are collected, they can be analyzed. Data analysis often involves a variety of calculations, conversions, graphs, tables, etc. The most common task a scientist faces is unit conversion. Units of time are acommon increment that must be converted. For example, suppose half of your data is measured in seconds,but the other half is measured in minutes. It will be difficult to understand the relationship between the data ifthe units are not equivalent. The following page provides a sample calculation.24Introduction to ScienceWhen calculating a unit conversion, significant digits must be accounted for. Significant digits are the digitsin a number or answer that describe how precise the value actually is. Consider the following rules:Table 1: Significant Digits RulesRuleAny non-zero number (1-9) is always significantAny time a zero appears between significantnumbers, the zero is significantZeros that are ending numbers after a decimalpoint or zeros that are after significant numbersbefore a decimal point are significantZeros that are used as placeholders are NOTsignificant digitsA zero at the end of a number with no decimalcan be a significant digitExample45 has two significant digits3.99 has three significant digits248678 has six significant digits4005 has four significant digits0.34000000009 has eleven significant digits45.00 has four significant digits15000.00 has seven significant digits62000000 has only two significant digits.0000000897 has only three significantdigits50 cm exactly has two significant digits(not rounded)Addition and subtraction problems should result in an answer that has the same number of significant decimal places as the least precise number in the calculation. Multiplication and division problems should keepthe same total number of significant digits as the least precise number in the calculation. For example:Addition Problem: 12.689 + 5.2 = 17.889 → round to 18Multiplication Problem: 28.8 x 54.76 = 1577.088 → round to 1580 (3 significant digits)Scientific notation is another common method used to transform a number. Scientific data is often verylarge (e.g., the speed of light) or very small (e.g., the diameter of a cell). Scientific notation provides an abbreviated expression of a number, so that scientists don’t get caught up counting a long series of zeroes.There are three parts to scientific notation: the base, the coefficient and the exponent. Base 10 is almost always used and makes the notation easy to translate. The coefficient is always a number between 1 and 10,and uses the significant digits of the original number. The exponent tells us whether the number is greater or25Introduction to Scienceless than 1, and can be used to “count” the number of digits the decimal must be moved to translate thenumber to regular notation. A negative exponent tells you to move the decimal to the left, while a positiveone tells you to move it to the right.For example, the number 5,600,000 can be written as 5.6 x 106. If you multiply 5.6 by 10 six times, you willarrive at 5,600,000. Note the exponent, six, is positive because the number is larger than one. Alternative,the number 0.00045 must be written using a negative exponent. To write this number in scientific notation,determine the coefficient. Remember that the coefficient must be between 1 and 10. The significant digitsare 4 and 5. Therefore, we know that 4.5 is the coefficient. To determine the exponent, count how manyplaces you must move the decimal over to create the original number. Moving to the left, we have 0.45,0.045, 0.0045, and finally 0.00045. Since we move the decimal 4 places to the left, our exponent is -4. Written in scientific notation, we have 4.5 x 10-4Although these…

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