Interview Notes. m) calorimeter b) temperature. o) isolated system d) heat of reaction. p) enthalpy of formation e) heat capacity

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1 TOPIC 1: Heat of Neutralization - The Strong versus The Weak: The heats of neutralization for mixtures of strong and weak acids with strong and weak bases will be determined and compared. A calorimeter must be designed and used to measure molar heat of neutralization for selected substances. Chemical Supplies: 1M solution each: hydrochloric acid (HCl), sodium hydroxide (NaOH), acetic acid (CH 3 COOH), sodium bicarbonate (NaHCO 3 ), general laboratory glassware and equipment. Other materials upon request Data sharing: You will be sharing your results in units of kj per mol 1. Terms you need to be able to define and explain: a) heat m) calorimeter b) temperature n) MSPS c) energy o) isolated system d) heat of reaction p) enthalpy of formation e) heat capacity q) calorimetry f) specific heat capacity r) acid g) enthalpy s) base h) endothermic t) neutralization i) exothermic u) heat of neutralization j) closed system v) strong acid or base k) dissociation w) weak acid or base l) heat flow x) Hess Law 2. What is the difference between a strong acid (or base) and a weak acid (or base)? 3. Would we expect a different outcome (in terms of heat released/change in temperature) when we mix a strong acid with a strong base, versus a weak acid with a weak base? Why or why not? Have some idea how to back this up using calculations. 4. Can we measure heat of neutralization directly? If so, how? If not, how are you going to figure out what the heat of neutralization is? 5. What research has already been completed in this area of chemistry? 6. What outside forces may affect the experiment? How will you control these? 7. What needs to be considered when making/finding a calorimeter? 8. What formulas do you need to calculate the number of kj per mol?

2 1) What question will your project attempt to answer? 2) What chemical or physical properties will you utilize when investigating this problem? 3) Write a balanced chemical equation to describe the change(s) you will see. 4) What is happening on the molecular level which makes this change possible? What is the driving force of this change? 5) What measures will you take in order to ensure the safety of your investigation? 6) What measurements will you need to calculate the desired result? 7) How could you reduce errors in your data (perhaps look up calorimeter constants and how they might be used here)? 8) What previous experiments have been done on this topic? 1) What is/are your dependent variable(s) of interest? 2) What is/are your independent variable(s) of interest? 3) What is/are your control variables? 4) What is/are unit(s) necessary in each of your chemical equations? 5) What unit(s) will you be measuring your experiment in?

3 TOPIC 2: Energy in food Which foods would you guess have the most energy? Students will be required to build an apparatus to analyze the amount of energy in several common varieties of snack foods. The type of snacks must be agreed upon between the groups doing this experiment. Chemical Supplies: Various types of snacks. General laboratory glassware and equipment. Other materials upon request. Data sharing: Results will be shared as Cal/g 1) Terms you need to be able to define and explain: a) Nutritional Calories b) Calories c) calories (not a repeat) d) Joules e) Ground state f) Heat g) Temperature h) Specific heat capacity i) Heat capacity j) Enthalpy k) Enthalpy changes l) Enthalpy of reaction m) Calorimetry n) Exothermic and Endothermic o) Thermochemical equation p) Molar enthalpy of combustion, vaporization, and fusion. q) Standard enthalpy of formation r) Standard enthalpy of combustion s) Reaction rates 3) What is the equation that will allow you to relate experimental measurements to molecular quantities that are different for different molecules? 4) What snacks will you use and why? General Questions: 1) What question will your project address? 2) What chemical or physical properties will you utilize in order to investigate this problem? 3) What chemical reactions are happening at the molecular level which make this reaction possible? 4) What measures will you take in order to ensure the safety of your investigation? 5) What are all the possible products of combustion? 6) What are the chemical compounds found in the snacks you have chosen? 7) How will you account for heat loss to the surroundings when burning food? 1) What is your dependent variable of interest? 2) What is your independent variable of interest? 3) What is your standard? Why do you need a standard?

4 TOPIC 3: Exploring rate of reaction by using a clock reaction. This is the hydrogen peroxide/ potassium iodide clock reaction. A solution containing hydrogen peroxide and hydrochloric acid is mixed with one containing potassium iodide, starch and sodium thiosulfate. After a few seconds the colorless mixture suddenly turns dark blue. This is one of a number of reactions loosely called the iodine clock. Students will examine the effect of reactant concentrations and temperatures on the rate of changing color. From the data, students will be able to determine the rate expression. Chemical Supplies: Hydrogen peroxide (H 2 O 2 ), sodium thiosulfate (Na 2 S 2 O 3 ), potassium iodide (KI), starch solution, Hydrochloric Acid (HCl), water, and general laboratory glassware and equipment. Other materials upon request Data sharing: k value and order of the reaction 1. Terms you need to be able to define and explain: a) Reaction Rate j) Colorimeter b) Rate law k) William Tell Overture c) Reaction order (zero, first, second) l) Polar and nonpolar d) Concentration m) Steric factor e) Collision theory, orientation n) Equilibrium f) Thermodynamics o) Instantaneous rate g) Activated complex p) Reaction mechanism h) Activation Energy q) Rate determining step i) Spontaneity r) MSDS 2. What is the balanced chemical equation for the reaction you are studying? 3. What is the equation that will allow you to relate experimental measurements to molecular quantities that are different for different molecules? 4. What factors affect reaction rate? 5. Research various iodine clocks. What are the differences between them? 6. How does the polarity of a molecule affect the iodine clock reaction? 1) What question will your project attempt to answer? 2) What chemical or physical properties will you utilize when investigating this problem? 3) Write a balanced chemical equation to describe the change(s) you will see. 4) What is happening on the molecular level which makes this change possible? What is the driving force of this change? 5) What measures will you take in order to ensure the safety of your investigation? 6) How will you find the rate expression for this reaction? 7) How would a colorimeter help you to find the reaction order? 1) What is/are your dependent variable(s) of interest? 2) What is/are your independent variable(s) of interest?

5 TOPIC 4: Buffer Capacity: Students will compare the capacity of two buffers, i.e. determine how much acid or base it will take to break the buffer. Students will make the final version of the two buffer systems. Chemical Supplies: The buffers: 0.1 M Acetate buffer at ph 4.5 [Sodium Acetate (NaCH 3 COO) and Glacial Acetic Acid (CH 3 COOH)]; 0.1M Borate buffer at ph 9.5 [Sodium Borate (Na 2 B 4 O 7 ) and Boric Acid (H 3 BO 3 ]; to break: 0.01 M Hydrochloric Acid (HCl), 0.01 M Sodium Hydroxide (NaOH), general laboratory glassware and equipment. Other materials upon request. Note: NaOH, Sodium Borate, and Boric Acid will all be solids, while acetic acid will be a solution. Data Sharing: Number of moles of NaOH and HCl used to break each buffer 1) Terms you need to be able to define and explain: a) Acid l) Chemical equilibrium b) Base m) Dissociation constant, K a and K b c) ph n) Buffer d) Neutralization o) Buffer capacity e) Strong acid or base p) Ionic equation f) Weak acid or base q) Net ionic equation g) Titration r) Titration curve h) Common ion effect s) Equilibrium equation i) Henderson-Hasselbalch equation t) Van Slyke equation j) ph probe u) Equivalence expression k) ph paper v) Le Chatlier s Principle 2) What are the main components of any buffer system? 3) How can we assure a buffer has a certain ph? 4) Step by step, how will you prepare an 0.1 M acetate buffer, ph 4.5 and a 0.1 M borate buffer, ph 9.5? Do you understand why 4.5 and 9.5 are important values here? 5) How will you determine whether the buffer is broken, i.e. the buffer capacity? 6) How do molarity and volume affect buffer capacity? 1) What question will your project attempt to answer? 2) What chemical or physical properties will you utilize when investigating this problem? 3) Write a balanced chemical equation to describe the change(s) you will see. 4) What is happening on the molecular level which makes this change possible? What is the driving force of this change? (this question is vital according to previous groups) 5) What measures will you take in order to ensure the safety of your investigation? 6) What is the main factor that affects the effectiveness of a buffer? 7) Write a balanced chemical equation to describe the change(s) you will see.

6 1) What is/are your dependent variable(s) of interest? 2) What is/are your independent variable(s) of interest? 3) What is/are your control variable(s) of interest? 4) What problems might you encounter while doing your experiment? 5) How is titration related to your experiment?

7 TOPIC 5: Calcium in Milk: The mass and percent composition calcium in multiple different samples of milk will be determined and compared. The milk samples will be provided and students will analyze them for calcium ion concentration using gravimetric analysis or titration. The results may be compared to the contents listed on the label. Chemical Supplies: Milk samples with differing amounts of fat (skim, 2%, whole, and buttermilk), Ammonium Hydroxide, magnesium chloride, ethanol (CH3CH 2 OH), Ethylenediaminetetraacetic acid otherwise known as EDTA, Eriochrome Black-T indicator dye, general laboratory glassware and equipment. Other materials upon request Data sharing: mg Ca per 8 oz of milk 1) Terms you need to be able to define and explain: a) Solution k) Contamination b) Solute l) Selective precipitation c) Solvent m) Indicator d) Analytical chemistry n) ph e) Gravimetric analysis o) MSDS f) Volumetric analysis (titration) p) Back titration g) Endpoint q) Buffer h) Equivalence point r) Titration i) Complexometric titration s) Titration curve j) Isolation and interference (in gravimetric analysis) 2) How will you make sure you will determine the amount of calcium only and not any other components of the milk sample? 3) How does an indicator work?. 1) What question will your project attempt to answer? 2) What chemical or physical properties will you utilize when investigating this problem? 3) Write a balanced chemical equation to describe the change(s) you will see. 4) What is happening on the molecular level which makes this change possible? What is the driving force of this change? 5) What measures will you take in order to ensure the safety of your investigation? 1) What is/are your dependent variable(s) of interest? 2) What is/are your independent variable(s) of interest? 3) What is/are your control variable(s) of interest?

8 Topic 6: Paper Chromatography: Chlorophylls, Carotenoids, and Anthocyanins What mixes of alcohol and water are needed to get the best chromatography results when comparing the chemical makeup of several different types of common leaves? What kind of structure will you build to aid in the chromatography? Chemical Supplies: Leaves of various plants from the grocery store, methanol, isopropyl alcohol, acetone, dichloromethane, general laboratory glassware and equipment. Other materials upon request. Data sharing: Retention factor at 30 minutes 1) Terms you need to be able to define and explain: a. Chromatography l. Additive color mixing b. Paper chromatography c. Chlorophyll a and Chlorophyll b, Carotenoids, Anthocyanins d. Pigment e. Solvent m. Subtractive color mixing n. Pi bond o. Conjugation p. MSDS q. Capillary action f. Mobile Phase r. Thin Layer chromatography g. Stationary phase s. Pheophytics h. Retention factor t. Xanthophylls i. Polarity, molecular polarity u. Chromatography strip j. Chromatography band v. Van Deemter Equation k. Solvent front w. Evaporation 2) What are the chemical structures of the pigments you are studying? 3) What is the equation that will allow you to relate experimental measurements to molecular quantities that are different for different molecules? 4) What factors effect chromatographic separation? 5) What does the polarity of the solvent have to do with the separation? 6) What parts of a pigment tend to be polar? 7) How do you plan to deal with the evaporation of your solvent? 1) What question will your project attempt to answer? 2) What chemical or physical properties will you utilize when investigating this problem? 3) What is happening on the molecular level which makes this change possible? What is the driving force of this change? How does this relate to the chromatography? 4) What measures will you take in order to ensure the safety of your investigation? 5) How are you planning to 1. What is/are your dependent variable(s) of interest? 2. What is/are your independent variable(s) of interest? 3. What is/are your control variable(s) of interest?

9 TOPIC 7: Vitamin C as a natural supplement. The mass percent composition of vitamin C in three common brands of orange juice. Chemical Supplies: Orange Juice, iodine, starch, general laboratory glassware and equipment. Other materials upon request Data sharing: Concentration of ascorbic acid in mg per 8 oz of Orange Juice 1. Terms you need to be able to define and explain: a) Solution, solute, solvent j) Redox potential b) Analytical chemistry k) Starch solutions c) Volumetric analysis (titration) l) Concentration d) Precipitation m) Free radical e) Titration n) Iodometric titration f) Stoichiometry o) Iodine solution g) Vitamin C p) ph h) Iodine q) Indicator i) Oxidation-reduction (redox) reactions 2) What are methods for determination of Vitamin C concentrations? 3) What happens when iodine is added to a starch solution? 4) What happens when iodine is added to a starch solution that also contains vitamin C? 5) What does the combination of iodine and starch form? 6) Why is Vitamin C useful for general overall health? 7) What precautions should be taken to make sure the starch and iodine solutions are fresh each time an experiment is run? 1. What question will your project attempt to answer? 2. What chemical or physical properties will you utilize when investigating this problem? 3. Write a balanced chemical equation, ionic equation, and net ionic equation to describe the change(s) you will see. 4. What is happening on the molecular level which makes this change possible? What is the driving force of this change? 1. What is/are your dependent variable(s) of interest? 2. What is/are your independent variable(s) of interest? 3. What is/are your control variable(s) of interest?

10 TOPIC 8: Does every gas have a molar volume of 22.4L at STP? Students will be given He, Ar, CO 2, and air. Students will design an experiment to determine the volume of 1 mole of these gases at STP. From the results, students will determine the causes of variations of the volume if there are any. Chemical Supplies: Helium, Argon, Carbon Dioxide, compressed air, and general laboratory glassware and equipment. Other materials upon request Data sharing: Volume of gas per mol 1. Terms you need to be able to define and explain: a) STP k) Diffusion b) Charles Law l) Effusion c) Gay Lussac s Law m) Equilibrium d) Ideal Gas Law n) Temperature e) Boyle s Law o) MSDS f) Ideal Gas p) Water vapor pressure g) Non ideal gas q) Polar h) Kinetic Molecular Theory of Gases r) Polarity i) Van der Waals Equation s) Avogadro s Law j) Dalton s Law of Partial Pressures t) Combined Gas Law 2. How are you going to transport the gas to do your experiment? 3. How are you going to get the mass of a gas that is lighter than air? 4. How do you expect a gas to behave when it is not an ideal gas? 5. How will you measure and collect the gas? 6. How will you ensure that your data is collected at STP? 7. How will you determine the pressure of the gas sample? 8. How do you expect a gas to behave when it is not an ideal gas? Why? 9. How will you determine the mass and volume of your gas? 1. What question will your project attempt to answer? 2. What chemical or physical properties will you utilize when investigating this problem? 3. What measures will you take in order to ensure the safety of your investigation? 1. What is/are your dependent variable(s) of interest? 2. What is/are your independent variable(s) of interest? 3. What is/are your control variable(s) of interest?

11 TOPIC 9: What is the best method to find the concentration of copper in a solution? A comparison of the effectiveness and relative accuracy of different methods of finding the copper (II) ion concentration will provide you with a challenging and wide-ranging investigation. Your group will be assigned two of the following methods of analysis: Titration, gravimetric analysis, electrochemical cells, or spectroscopy. Students will collaborate to determine the best method for analyzing the concentration of the copper solution. Chemical Supplies: Cu +2 containing unknowns, general laboratory glassware and equipment. Other materials upon request. There may be specific requests of methods as we go further into the project. Data sharing: Percent error from known solution concentration 1) Terms you need to be able to define and explain: a. Spectroscopy b. Colorimetry l. Oxidation number Half reaction c. Titration d. Gravimetric analysis e. Electrochemical analysis m. Oxidation n. Reduction o. Redox equation f. Analytical chemistry p. Voltaic cell g. Nernst equation q. Cell potentials h. Precipitate r. Cell potential formula i. Concentration s. Electrolyte, electrolysis and j. Solubility electroplating k. Molarity t. MSDS u. Hydrate 2) What is the electronic configuration structures of copper ions and elemental copper? 3) What is the equation that will allow you to relate experimental measurements to molecular quantities (amount of copper)? 4) Draw an AufBau diagram for copper and copper (II) ion. 5) How do solubility rules relate to the AufBau diagram mentioned above? 6) Spend some time figuring out which vocabulary terms go with which method. 1. What question will your project attempt to answer? 2. What chemical or physical properties will you utilize when investigating this problem? 3. Write a balanced chemical equation to describe the change(s) you will see. 4. What is happening on the molecular level which makes this change possible? What is the driving force of this change? 5. What measures will you take in order to ensure the safety of your investigation? 1. What is/are your dependent variable(s) of interest? 2. What is/are your independent variable(s) of interest? 3. What is/are your control variable(s) of interest?

12 TOPIC 10: Find the cheapest way to plate copper on materials Electroplating is an economically important process, often used to reduce corrosion or improve the appearance of objects. During electroplating a thin layer of a desirable metal is deposited. Students will collaborate to determine the best method to determine the time and amount to plate a good quantity of copper on a material. Chemical Supplies: Copper Sulfate solution, general laboratory glassware and equipment. Other materials upon request. There may be specific requests of methods as we go further into the project. 1) Terms you need to be able to define and explain: a. Activity series b. Anode/Cathode c. Electrolytic cell d. Electrochemical analysis e. Transition metal f. Battery/cell g. Salt bridge h. Nernst equation i. Suspension j. Concentration k. Oxidation number Half reaction l. Oxidation m. Reduction n. Redox equation o. Voltaic cell p. Cell potential q. Standard potential r. Standard reduction potential s. Electrochemical cell potential t. Cell potential formula u. Electrolyte, electrolysis and electroplating v. Faraday s Law of Electroloysis w. Mass, pulse, brush, electroless plating 2. What is the electronic configuration structures of copper ions and elemental copper? 3. What are the equations that will allow you to relate experimental measurements to molecular quantities (amount of copper)? 1. What question will your project attempt to answer? 2. What chemical or physical properties will you utilize when investigating this problem? 3. Write a balanced chemical equation to describe the change(s) you will see. 4. What is happening on the molecular level which makes this change possible? What is the driving force of this change? 5. What measures will you take in order to ensure the safety of your investigation? 6. Write the half-reaction that occurs at the anode of the electrolytic cell. Is it oxidation or reduction? 7. Write the half-reaction that occurs at the cathode of the electrolytic cell. Is it oxidation or reduction? 8. Write a descriptive paragraph or two that explains both the flow of copper ions and electrons through the system. 9. How many amperes were flowing through the electrolytic cell? Use the mass of copper plated and the time that it took to plate the nail to find this value. 1. What is/are your dependent variable(s) of interest? 2. What is/are your independent variable(s) of interest? 3. What is/are your control variable(s) of interest?