CTDLGuo

Summary In this lab, students were given the task of finding the percent ionization of the acetic acid, CH3CO2H, in vinegar. Students would slowly add in sodium hydroxide, a base, into the acetic acid until it was neutralized, and showed a pale pink. Materials included a funnel, a burette, beakers, a hot plate, an Erlenmeyer flask, a graduated cylinder, a pippette, and a magnetic stir bar. Data Percent Ionization of Vinegar Our percent ionization of vinegar is 0.45% . This is such a low number because it is a weak acid, so the molecules doesn't seperate easily, and so not all of them split into ions. Photos Our setup Trial #1 Analyte (Failed) Trial #2 Analyte at Equivalence Point

Introduction The purpose of the lab was for students to, using a given graph of solubility, decipher whether an unknown substance is NaCl, NaNO2, or KNO3. Students were not given a procedure, so they had to design their own. Materials included beakers, a hot plate, a balance, a thermometer, a graduated cylinder, and a stirring rod.  Solubility- ability for a solute to dissolve in a solvent Solubility Curve- a graph of the variation of changing temperature of the solubility of a given substance in a given solvent Solute- smaller component of a solution that is dissolved into a solvent Solvent- larger component of a solution that dissolves the solute Solution- liquid mixture where the solute is evenly dispersed in the solvent Saturated Solution- solution containing the maximum concentration of a solute dissolved in the solvent Our Set-Up Procedure 1) We first obtained materials: beakers, a hot plate, a balance, a thermometer, a graduated cylinder, an...

Summary In this lab, students were given a two tablets of Alka Seltzer and were told to collect the CO2 gas it gave off. The crushed Alka Seltzer powder mixed with water would cause the balloon to inflate, then measuring the circumference of the balloon using a string. Then, using the ideal gas law and finding the volume of the sphere, students could determine the mass of the gas. Data Table and Calculations  Analysis Questions 1) When we were transferring the water from the balloon to the graduated cylinder, some water splashed out. Also, while we where measuring the circumference of the balloon with the string, it wasn't perfectly in the middle. 2) The error from the above question of losing water while transfering it would cause the number of moles of CO2 to be too large. This is because the volume of the water that fits in the balloon would be greater, and therefore when you solve for the amount of moles of CO2 in the ideal gas law, it would turn out larger....

Summary In this lab, students were asked to design a procedure to determine an unknown metal's specific heat in order to identify the mystery metal. Each group was given two styrofoam cups (one small one big), water, a thermometer, tongs, and a beaker. Our group decided to measure the specific heat by heating the metal in boiling water, then place it into cool water, and see the temperature difference. The difference would explain the metal's gain of energy and heat.  Set Up Procedure 1) Obtain the materials. Set up and start heating the the hotplate, and place a beaker filled with water onto the plate. Poke a hold into the middle of the small styrofoam cup.  2) Mass the unknown metal sample. 3) Mass the large styrofoam cup, mass the large cup filled with water, and then subtract those to get the mass of the water itself. Take the initial temperature of the water in the styrofoam cup. 4) Gently place the metal into the beaker. 5) When the w...

Pre-lab and Data Tables Calculations and Results 2) Explain the differences in the difference in temperature of these substances as they evaporated. Explain your results in terms of intermolecular forces. There are differences in the temperature of the substances as they evaporated is because of the different heat absorptions. In order to change a liquid to a gas, you must have enough energy to break the intermolecular bonds of the liquid. As the liquid evaporated into gas, it absorbs energy, in the form of heat, from the temperature probe. When the substance absorbed in the filter paper was evaporating, whether the drop of the temperature would be drastic or mild was due to how much energy was needed to break the intermolecular bonds.   3) Explain the difference in evaporation of any two compounds that have similar molar masses. Explain your results in terms of intermolecular forces.  The difference in evaporation of any two compounds that have similar ...

Summary In this lab, the students were asked to combine substances of acids and alcohols and notice the differences of the smells. From this, the students learned how molecules can be changed into different molecules using chemistry.  Students were given three test tubes, labeled I, E, and M. In test tube I, students placed in 10 drops of isopentyl alcohol, 10 drops of glacial acetic acid, and 1 drop of concentrated sulfuric acid. In test tube E, students placed in 10 drops of ethyl alcohol, 10 drops of glacial acetic acid, and 1 drop of concentrated sulfuric acid. And in test tube M, students measured in 0.15 g of salicylic acid, 12 drops of methyl alcohol, and 3 drops of concentrated sulfuric acid. The students were asked to record the smell of all the substances into a data table.   Our test tubes reacting inside the hot water Data Table Analysis Questions 1) The odors of the three mixtures after heating are sweeter compared to before heat...

What was the biggest challenge you had while playing? The biggest challenge I had while playing was trying to say the electron configuration for Au, or gold. What was one thing you learned through playing? One thing I learned through playing is how to do the electron configuration for Au, and also how to strategically place "battleships" using reverse psychology to have my opponent not be able to guess where they were placed. Our ending boards

Summary In this lab, students were given many different substances to hold over a flame and were asked to observe the colors of the flame produced. This helped demonstrate the relationships of the flame colors and the certain atoms contained in compounds. Pre-lab Questions 1) What is the difference between ground state and an excited state?  Ground state is the most stable state where all the electrons are in the lowest energy levels. On the other hand, an excited state is where the electrons are in an unstable arrangement, and will go back to their normal positions of lower energy. 2) What does the word "emit" mean? The word "emit" means to "produce and discharge", especially in gas or radiation. 3) In this experiment, where are the atoms getting their excess energy from? In this experiment, the atoms are getting their excess energy from the heat of the bunson burner's flame, where the electrons can reach an excited state. 4) Why do ...

Purpose of Lab The purpose of this lab was to educate students on mass-mass relationships. Students can learn more on how these relationships occur in chemical reactions and in balanced chemical equations.  Lab Manual Questions  Our Product After Evaporation Possible Error Sources of possible error in our percent yield include how our substance had too much acid evaporation, which may have caused changes to our actual yield. Also, when we were adding the acid to the NaHCO3 with a dropper, we dropped the acid a little quicker than we should have, contrary to how the instructions tell us to gradually drop the acid in.

Hydrate Before and After Heating: Before heating  After heating Calculations: (Our balance only read up to 3 sig figs for the percent error, so we just used 3 sig figs) 5a) My answer is 0.0144321931 mol for the moles of water evaporated. I found this by multiplying the grams of water evaporated by the conversion factor of 1 mole/18.01528g (the molar mass of H2O). 5b) My answer is 0.0033832679 mol for the moles of CuSO4 that remain in evaporating dish. I found this by first subtracting the mass of the evaporating dish by the mass of the evaporating dish and remaining anhydrous salt, and got 0.54g. I then multiplied the 0.54g by the conversion factor of 1 mol/159.6096g (the molar mass of CuSO4). 5c) To find the ratio of moles of CuSO4 to moles of H2O I divided 0.0144321931 mol and 0.0033832679 mol by the smallest, which was 0.0033832679 mol. 0.0033832679 mol/0.0033832679 mol was 1, while 0.0144321931 mol/0.0033832679 mol was approximately 4.  5d) Based ...

Purpose and Summary           The purpose of this lab was for students to practice identifying substances using limited information. In this particular lab, the mass, number of moles, and number of particles were given. From this lab, students can also understand the concepts of moles and the relationships between moles and molar mass.         Each group was given a bag, either from Set A or Set B, that held an unknown substance. After the group identified the substance, they had to solve a bag from the different set. The bags also had information for clues: Bag A had the mass of the empty bag and the number of moles, and Bag B had the mass of the empty bag and the number of particles listed. Answers         A6 is Sodium Chloride.         B6 is Zinc Oxide. Determining the Identity         My partner and I first recieved the bag B6 from Set B. We started off by first weighin...

The purpose of this lab was to be able to explore various chemical reactions and be able to recognize the patterns of changing the reactants to products.  My favorite reaction was Reaction #1, where there was a reaction between magnesium and heat. We took a piece of magnesium and put it over the laboratory burner, then when it ignited we removed it from the fire and put it into an evaporating dish. The appearance of our reactant was a metallic gray and the temperature of it was cool. Then, in the end the properties of the product was white/gray, flakey, and the temperature was very hot. There was evidence of a chemical reaction because of the blinding white light that was a effect of the ignition, and the burning of the magnesium.  Reaction 1: the ignition of magnesium and heat Balanced chemical reaction for each reaction Classifications for each reaction

The purpose of this lab was to investigate chemical reactions that cause solids to form. Our wellplate of the reactions  Net Ionic Equations What surprised me the most was how quickly the precipitate formed, especially in reaction 6 with NaOH and Cu(NO_3)_2. 

        The goal of the activity was to piece together all the formulas to their names and create a 4x4 puzzle.         The biggest challenge while completing this activity was finding the correct pieces to match because all the pieces were scattered around and hard to find.         My biggest contribution to the group was helping find a puzzle piece when someone asked for it, and also gradually building squares on my own so, in the end, we could combine all the built sections together. Our ending puzzle

Purpose of the Lab The purpose of this lab was to practice our abilities of finding the total and average mass of isotopes, determining percent and decimal abundance, and finding the average atomic mass. We did this with a given random combination of skittles, m&m's, and pretzel m&m's.  Average Atomic Mass (0.603x0.864)+(0.30x1.02)+(0.10x2.09) = 1.036 = 1.0.  Conclusions 1. Ask a group nearby what their average atomic mass was. Why would your average atomic mass be different than theirs? The other group's average is 1.23. Our average atomic mass might be different because each isotope--skittles, m&m's, and pretzel m&m's--had a different total number, and thus a different total and average mass. This affected the average mass because the formula for it, average atomic mass = (decimal abundance of isotope 1 x mass of isotope 1) + (decimal abundance of isotope 2 x mass of isotope 2) + (decimal abundance of isotope 3 x mass of is...

1. Why is it important that only the wick and not the filter paper circle be in contact with the water in the cup? It is important so the water could be spread from the center to the edge and create a pattern. If the filter paper circle is in contact with the water, then there wouldn't be a directional flow, and there wouldn't be a clean design. 2. What are some of the variables that will affect the pattern of colors produced on the filter paper? Some variables are the brand of the ink, the distance the ink was placed from the center, what type of design was drawn (dots, lines, squigly lines), and the size and thickness of the dots and lines made. 3. Why does each ink seperate into different pigment bands? Each ink seperates into different pigment bands because depending on their characteristic physical properties, they travel up the filter paper and diffuse at different rates. The partitioning of the components of the mixture between solvent and the filter paper dete...

Purpose: What is the purpose of performing this experiment? What problem are you trying to solve? The purpose of performing this experiment was to find the relationship between denstiy, mass and volume. The problem we are trying to solve is determining the thickness, or height, of our aluminum foil in millimeters given a ruler, a scale, and the density of the foil, 2.70 g/cm^3. Procedure:  How did you actually perform PART II of your experiment? First, using the given scale, we weighed the aluminum foil, where we got 0.6 grams. Next, using the given ruler, we measured the length and the width, where we got 11.81 cm and 12.35 cm. Then, using the formula of density=mass/volume, we substitute in the values we know so far, and have the equation of 2.70 g/cm^3 = 0.6/V. When we solve this, we get V=0.2 cm^3. Finally, we can use the formula of volume = length x width x height, and plugging the values in we get 0.2 = 12.35 x 11.81 x H, and simplifying this we get H=0.001371 cm. Th...

           My partner and I are given the task of trying to determine the mass of a plastic block using its density and volume. We had to have a percent error of less than 5%. The only tool available for us is a ruler, and we were given the density, 2.70 g/cm^3.            We started off by determining to use the formula of density=mass/volume to find the mass. First, we needed to find the volume so we used the ruler to measure the length, height, and width of the block, where we got 2.50 cm x 2.50 cm x 2.50 cm. We multiplied these measures together to get the volume, using the formula of volume = length x height x width , where we got 15.625 cm^3. Plugging these values into the formula of  density=mass/volume , we got 2.70 g/cm^3 = mass / 15.625 cm^3, and we solved the equation to get 42.1875 grams. Using the properties of significant figures, 42.1875 was simplified to 42.2. Thus, our calculated mass was 42.2 grams. ...