Dilute 2.6 Lab Report

The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in

The purpose of this lab was to identify unknown bacteria cultures using various differential tests, and my unknown bacteria is #17. The identification of these unknown cultures was accomplished by separating and differentiating possible bacteria based on specific biochemical characteristics. Whether the tests performed identified specific enzymatic reactions or metabolic pathways, each was used in a way to help recognize those specifics and identify the unknown cultures. The differential tests used to identify the unknown cultures were Gram stain, Catalase, Mannitol Salt Agar (MSA), Blood Agar, Novobiocin, Coagulase, and DNAse (Alachi, 2007).

Table 2: Consists of color extract taken from a red cabbage for a natural indicator. The pH reading that was measured by using the pH meter and the result of the pH reading to determine whether the solution was acidic or basic.

From the calculations in the data analysis, the actual percent composition of magnesium is 65.3% ± 1.7%, the actual percent composition of oxygen is 34.7% ±2.5%. The purpose of this lab was achieved as the percent composition of the magnesium oxide was determined and was used to test the law of definite proportions. The hypothesis was mostly correct as the results demonstrated that the actual percent composition was only slightly greater/lesser than the hypothesized percent composition. However, the actual percent composition may have been affected by several limitations during this investigation.

From the results that were acquired from mixing the liquid reagents with each powder, it was determined that Unknown Mixture #1 consisted of baking soda and cornstarch. When individually testing the substances from Unknown Mixture #1 with the liquid reagents, a few noticeable reactions occurred. Mixing baking soda with vinegar caused bubbling to occur. This is because a neutralization reaction took place between the two reactants. In this reaction, sodium bicarbonate(baking soda) reacts with vinegar and produces sodium acetate, water, and carbon dioxide(HC2H3O2(aq) + NaHCO3(aq) NaC2H3O2(aq) + H2O(l) + CO2(g) ). The gaseous carbon dioxide most likely tried to escape into the atmosphere and caused the bubbling to occur. Another noticeable reaction

2. (5 pts) List and explain the names and affiliations of the various characters/stakeholders in this story – I’m looking for us to use the story to map out the complexities that are generally associated with solving public health puzzles – the stakeholders you list and explain here should apply to many of the cases we consider going forward.

Identifying the three components of the unknown mixture, a 1.5 g sample was obtained and dissolved in 30 mL of diethyl ether. This solution was then poured into a separatory funnel with a funnel with the stopcock closed, and inverted twice so that there would be a formation of different layers in the mixture. In order to extract the base from the mixture, approximately 14 mL of 10% hydrochloric acid was added into the funnel and mixed. To mix the hydrochloric acid thoroughly the funnel was gently shaken with the pressure released by removing the stopper intermittently. The solution then separated into an aqueous layer at the bottom, and an organic layer at the top (containing the acid).1 The aqueous layer (containing the base) was released into an

2. When 2.00 g of NaOH were dissolved in 49.0 g water in a calorimeter at 24.0 ˚C, the temperature of the

Enzyme Concentration: Cuvette 2 gradually increased every twenty seconds for two minutes and contained 1 milliliter of the enzyme (figure 1). Cuvette 3 slowly increased but was a bit faster than cuvette 2 every twenty seconds for two minutes and contained 2 milliliters of the enzyme (figure 1). Cuvette 4 was started lower then cuvette 2 and 3 then made a significant increase every twenty seconds for two minutes and contained 4 milliliters of enzyme (figure 1). The average rate of absorbance for cuvette 2, 3, and 4 were .0013 au per second, .0028 au per seconds, and .0041 au per second.

The mean voltage of the battery terminals while connected to the identification resistors is presented in Figure ‎4 12. These samples have been pulled out from the voltage sensor of the PEB panel. The voltage decreased as expected from 12.53 to 12.5 during first 20 seconds of connection to the

The exponential growth of human population, caused an unprecedented problem for the global ecosystem. (Carolina EcoKits, 2012) The increase in pollution brought upon great fear and concern about what types of contaminants were in the foods and water supply for citizens. In 1977, the Clean Water Act was passed, the act ensured that any release of pollutants at toxic levels into any water source was forbidden. (Carolina EcoKits, 2012) It allowed for the Environmental Protection Agency (EPA) to set guidelines and standards for how pollutants were emptied in navigable waters. (Carolina EcoKits, 2012)

In the method of continuous variations the total number of moles of reactants is kept constant for the series of measurements. Each measurement is made with a different mole ratio of reactants. A mole ratio is ratio between the amounts in moles of any two compounds involved in a chemical reaction. Mole ratios are used as conversion factors between products and reactants in many chemistry problems.

I am Kristal Lopez in your Chemistry 120B– lab section 8 on Tuesdays and Thursdays from 11am to 1:50pm. I am writing to you because yesterday, Thursday September 22, in lab I forgot to get my lab notebook sheet signed and turn in the carbon copy. I was wondering if there was anything I could do about it? Thank you for your time and I hope you have a nice day.

Background Information: According to Steven S. Zumdahl and Donald J. DeCoste (Introductory Chemistry: A Foundation), “a double replacement reaction occurs when two cations and two anions are transferred. A precipitation reaction takes place when two aqueous solutions dissolve in water, and a solid forms between one of the cations and one of the anions” (Zumdahl/Donald 187). Zumdahl and Donald also say that evidence of a precipitate includes a color change, gas production, transfer of electrons, or the formation of water. All of these types of evidence occurred in this lab. Signs that a reaction has taken place

Observe • To identify the molar solubility and the constant associated with it for calcium hydroxide. • To conduct an experiment regarding how the effect common ion has on the overall solubility of calcium hydroxide. Procedure 1. Molar Solubility and Solubility Product of Calcium Hydroxide • Obtain a prepared saturated solution containing calcium hydroxide.