The lab started off by measuring critical materials for the lab: the mass of an an empty 100 mL beaker, mass of beaker and copper chloride together(52.30 g), and the mass of three iron nails(2.73 g). The goal of this experiment is to determine the number of moles of copper and iron that would be produced in the reaction of iron and copper(II) chloride, the ratio of moles of iron to moles of copper, and the percent yield of copper produced. 2.00 grams of copper(II) chloride was added in the beaker to mix with 15 mL of distilled water. Then, three dry nails are placed in the copper(II) chloride solution for approximately 25 minutes. The three nails have to be scraped clean by sandpaper to make the surface of the nail shiny; if the nails are not clean, then some unknown substances might accidentally mix into the reaction and cause variations of the result.
each paper remained it's original color, thus concluding that the unknown was neutral. These results also led the students to believe the unknown was CaCl2 since it was listed in the neutral column. After the litmus test was conducted the students added a few drops of Na3PO4 to the unknown. When these two were combined a precipitate was formed. This final test on unknown F verified that it was CaCl2.
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.
The name of the lab is “Drops on a Penny.” I was expected to find the independant variable, dependant variable, write a hypothesis, and test the experiment. After testing the experiment multiple times, I needed to find the average amount of drops for each trial, graph them, and tell what kind of relationship it is. The last thing I needed to do was rewrite the details of the project and write a conclusion. The point of the experiment was to have the students get used to the idea of a lab, and get familiar with independent and dependent variables.
The results do not support the hypothesis that a higher surface area to volume ratio would result in sulphuric acid being diffused into the agar cubes in the shortest amount of time. This is evident in the results as the exact opposite to what was predicted occurred. Instead of the smallest cube with the largest surface area to volume ratio of 1cm3 having the quickest diffusion rate, it conversely took the longest at 0.092 cm3 per second, whilst the 2cm3 cube with 0.0384 cm3 per second took the least amount of time. This directly refutes the hypothesis. There was also no consistent trend evident in the results.
No Error (D) Answer: A There is (A) / few time (B) / for preparation. (C) / No Error
This could include setting up the experiment incorrectly, or a simple
However, the experimental values were different due to human error. Error Analysis Discuss the
I selected the acid-test ratio for my sixth item to study as this targets M1 and other forms of assets that are easily convertible to cash. In 2013, Kraft appeared to have been in decent shape to pay off their current liabilities. In 2014, they fell further into the red. While this is not uncommon to have a low acid-test ratios, it indicates that Kraft would have difficulties paying off their liabilities. Something positive for Kraft having a low acid-test ratio is they have invested much of their highly liquid assets back into the company.
Properties of Substances Express Lab 1)The purpose of this lab was to compare the physical properties of different types of solids and how the properties of solids are determined by their intermolecular forces and their intramolecular bonds. Then we were to classify each type of solid as either ionic, metallic, non-polar molecular, polar molecular, or network. Paraffin wax classified as a non-polar molecular, Silicon dioxide was classifies as a network, Sodium chloride was classified as ionic, Sucrose was classified as polar molecular and Tin was classified as metallic. (2)The intermolecular forces that are present in Paraffin wax are dispersion forces, because it is non-polar and carries a negative charge. Followed by Sucrose that has
Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter.
Aim: To find out the relationship between the greater concentration of sodium thiosulfate when mixed with hydrochloric acid and the time it takes for the reaction (the time it takes for the solution to turn cloudy) to take place and to show the effect on the rate of reaction when the concentration of one of the reactants change. Introduction: The theory of this experiment is that sodium thiosulfate and hydrochloric acid reach together to produce sulfur as one of its products. Sulfur is a yellow precipitate so, the solution will turn to yellow color while the reaction is occurring and it will continue until it will slowly turn completely opaque. The reaction of the experiment happens with this formula: “Na2 S2 O3 + HCL =
Introduction The goal of the experiment is to examine how the rate of reaction between Hydrochloric acid and Sodium thiosulphate is affected by altering the concentrations. The concentration of Sodium thiosulfate will be altered by adding deionised water and decreasing the amount of Sodium thiosulphate. Once the Sodium thiosulphate has been tested several times. The effect of concentration on the rate of reaction can be examined in this experiment.
Practical I: Acid-base equilibrium & pH of solutions Aims/Objectives: 1. To determine the pH range where the indicator changes colour. 2. To identify the suitable indicators for different titrations. 3.
Abstract The unknown concentration of benzoic acid used when titrated with standardized 0.1031M NaOH and the solubility was calculated at two different temperatures (20◦C and 30◦C). With the aid of the Van’t Hoff equation, the enthalpy of solution of benzoic acid at those temperatures was determined as 10.82 KJ. This compares well with the value of 10.27KJ found in the literature.