In this experiment, we sought to determine what type of iron was used in the nails which we utilized in our reaction. In order to determine this, we added the said nails into a mixture of H2O and CuCl2 with the intention of reacting the two to create copper. Because of the law of conservation of mass, the creation of copper had to take mass from one of the reactants, in this case, iron. We observed the mass of the iron nails decrease between the start and the end of the lab, and we then converted that mass in grams into moles of iron and did the same with the amount of copper that we recorded after the decanting process. We used these two measurements to calculate the mole ratio between iron and copper. By doing this, we were able to share our table’s ratios …show more content…
This type of lab heavily utilizes the concepts of stoichiometry. Stoichiometry looks into the relationship between the relative amounts of substances that are part of a reaction. You can also use stoichiometry for unit conversions, in this case, moles. Moles are a vital unit of measurement that is used to calculate and compare large quantities of small things. Chemists use moles rather than mass when determining relationships between multiple substances because they work with extremely small particles, so using the mass wouldn’t be productive. They created the mole so they could more accurately compare relationships between multiple substances. Our class average for the mole ratio of Fe:Cu was 0.80 mol Fe/mol Cu, while my table’s mole ratio was 0.94 mol Fe/mol Cu. Due to my use of the former mole ratio in my calculations, I determined that my table’s nails were primarily made up of Iron III. I recorded several qualitative observations, and they can be used as justification for a chemical reaction occurring in the first place. For example, I found that the beaker began to warm soon after we added the nails into the CuCl2
An error that could have been present during the lab includes not letting the zinc react completely with the chloride ions by removing the penny too early from the solution. For instance, the percent error of this lab was 45.6%, which was determined by the subtraction of the theoretical percent of Cu 2.5% and the experimental percent of Cu 3.64% and dividing by the theoretical percent of Cu 2.5%. This experiment showed how reactants react with one another in a solution to drive a chemical reaction and the products that result from the
Question3: Experiment 3 The unknown acid sample was 1 • Monoprotic Acid Trails Initial NaOH solution (mL) final NaOH solution (mL) The volume of NaOH to titrate the acid (mL) Amount of Unknown Acid sample 1 (g) The moles of the Unknown Acid (mol) Molar mass of the Unknown Acid (g/mol) A 3.38 28.31 24.93 0.150 0.0026 57.69 B 0.18 29.32 29.14 0.175 0.0029
Introduction The purpose of this Lab was to identify the density of the unidentified object and determine what substance the unidentified object given by the teacher was. The density calculated in the experiment will stay the same because the density of the unidentified object will stay constant. The Independent Variable of this experiment was the calculated density and the unidentified object given. The Dependant Variable for this experiment was the density.
We were asked to correctly communicate these findings as we tested each of the substances she had encountered with both water and hexane. In experiment number three, The Relationship Between the Volume of a Gas and the Temperature, we where given a list of materials and asked to come up with our own procedure, which we did using zip lock bags filled with air, and submerged fully in a measured amount of water in order to find the volume, and then the change in volume when the temperature of the water was increased. In the fourth experiment we were asked to find the temperature of heated water, based on the cold and warm water. The experiment also required that each section be preformed several times in order to ensure accuracy, and also asked that the experimental responsibilities be split up between lab partners, each doing a section of the testing. This gave us an opportunity to work together with our fellow lab partners, with no one person doing the bulk of the work.
In order to find the amount of a product made during a double displacement reaction, the product has to be separated from the solution. From this number of moles of precipitate can be calculated. From there the number of moles of reactants can be calculated using the mole ratios of the particular reaction that occurred. As seen in Table 5 it is shown that by finding out the number of moles of the unknown, the molar mass of the unknown can be calculated. From the found mass of the unknown compound, the mound of the original ion can be found.
The “Yields of Copper” chart show the different amounts of that were produced during the original experiment. The initial amount shows the amount that was used in procedure one . The final theoretical amount shows the amount of copper that the reaction for the fifth procedure should give you when using stoichiometry to find the amount of copper in that reaction. Conclusion:
Different Mole Ratios And It’s Reactions Introduction: Chemical reactions play an important role when it comes to mole ratios.
The lab specialist shall evaluate the evidence and submission information based on his/her training and experience, and shall determine which items will be analyzed. Lab specialist shall evaluate which items to analyze in a case based on several factors. These factors include nature of potential charge(s), location of items, and the nature of the item (i.e., biohazard, insufficient sample, etc.). If a case approved for analysis consists of multiple items that are all residue amounts, analysis shall be performed on at least one item. If a controlled substance is identified in the first item analyzed, no other items shall be analyzed.
Using the equation m = ΔTf/Kf , the molality of the unknown solution was found. Then, moles of unknown were calculated, which was used to calculate the average molar mass of unknown. Theory: After the experiment was completed, the data
I. Purpose: To experimentally determine the mass and the mole content of a measured sample. II. Materials: The materials used in this experiment a 50-mL beaker, 12 samples, a balance and paper towels. III.
The limiting reagent in this lab was iron. Iron was the obvious limiting reactant because the 4.00 grams of iron was used to determine that 11.43 grams of copper sulfate would be necessary in the equation. Also, an extra 25% of copper sulfate was added to make sure there was enough copper sulfate in the reaction since it was the excess in the reaction. The theoretical yield of the reaction was 4.551 grams of copper. The theoretical yield is an amount predicted by stoichiometry and assumes that the limiting react is used completely; the yield was determined through stoichiometry by converting the amount of iron into the amount of copper in the reaction.
Ratios are defined as a relationship between two numbers which is obtained when one number is divided by another number. After the data is simplified thru ratios you can then generalize what the information says. The chapter then discusses the density ratio which is the simplified way of comparing the mass of a volume. Finding the ratio of mass to volume is called density.
Verna Wang Hannah Palmer CHEM 101-069 Lab 11-19-16 Stoichiometry and Limiting Reagents Lab Report Purpose: We are using the reaction of sodium hydroxide and calcium chloride to illustrate stoichiometry by demonstrating proportions needed to cause a reaction to take place. Background: Just like a recipe would call for a specific amount of one ingredient to a specific amount of another, stoichiometry is the same exact method for calculating moles in a chemical reaction. Sometimes, we may not have enough of or too much of one ingredient , which would be defined as limiting and excess reagent, respectively.
Use molar proportion to determine unknown quantities of moles. Do this by setting two molar ratios equal to each other, with the unknown as the only value to solve. Convert the mole value you just found into mass, using the molar mass of that substance. Because atoms, molecules, and ions react with each other according to molar ratios, you'll also encounter stoichiometry problems that ask you to identify the limiting reactant or any reactant that is present in excess. Once you know how many moles of each reactant you have, you compare this ratio to the ratio required to complete the reaction.
Measurements and significant figures are important in Chemistry because it shows how accurate something is, and it shows which place value is the estimated one if/when used correctly. In this lab, the density for water that was found is 0.99g/mL and the percent error was 1%, and 1% is good. An error that could have occurred while finding the density for water was that the measurement were not exactly correct because not everything is going to be perfect. The density for Copper that was found was 8.5g/mL, and the percent error was 5%, and 5% is fair.