Calorimetry Lab

If there is an additional unmeasured amount of water in the Erlenmeyer flask, then this would reduce the concentration of the HCl, and therefore reduce the molarity. The volume of the amount of HCl solution added would increase, yet the concentration of the HCl would remain the same, which would ultimately result in the molarity of the HCl being lower than in reality.

1. In the human blood, there is the bicarbonate buffer system. CO2 is released from cellular respiration and then taken up by red blood cells. Next, it is changed to carbonic acid which dissociates to form bicarbonate and H+ ions.

During this lab I learned how to convert the mass of a compound to the number of moles and then to the number of molecules, I also learned how to determine the concentration of a

Purpose: To find the relationship between the mass and the volume of the four samples.

In this experiment, a mixture of unknown #3 was used. That mixture had acid, base, and neutral. We added solvent to the unknown. It is important to know the density of the solvent in order to determine which is the aqueous layer and which is the organic layer. If the solvent that has more density than water, so the organic layer will be the lower layer, while if the solvent has lower density than water, the organic layer will be the upper layer. This will make an error if the determination of the layers was wrong after added the strong acid or the strong base. We added 5% HCl to the mixture in order to separate the base in the aqueous layer and form its salt. Same thing, we add 5% NaOH to the mixture in order to separate the acid and form its salt. In order to recover the base, we add 10% NaOH to the HCl extraction. The result will be salt with a base. Same thing for the acid, in order to recovered it, we added 10% HCl. The reaction will give us salt with an acid. For the neutral, we added sodium sulfate as a drying reagent in order to dry water and separate the neutral part as pure.

The main purpose of the lab “Determination of the Formula of a Copper Oxide” was to determine the formula of a copper oxide. Specifically, this is a compound of copper combined with oxygen. This was to be done by heating the copper oxide thoroughly until all of the oxygen had been driven off. To accomplish this experiment, we first had to take and measure the mass of a specified color of copper oxide, ours being red. Then, we used a fischer burner to provide the heat needed for the split of copper oxide, in which our amount resided in a test tube. But, in order for the copper to not recombine with oxygen that could be found in the surrounding atmosphere of our lab, we also had to have a flow of methane gas into the test tube that fed into

The mass of salt (.26 grams) was then divided by the total mass of mixture (3 grams) and then multiplied by 100 to get 8.7% salt. The mass of sand was determined by subtracting the 100mL beaker with filter paper and sand (54.57 grams) by the the empty 100mL beaker with filter paper weighing 52.74 grams, to get 1.83 grams of sand. The mass percent of sand was determined by dividing the 1.83 grams of sand by the mass of mixture (3 grams) and multiplying by 100 to get 61%

Table1: pH of the pure NaOH solution, the NaOH mixed with Benzophenone solution. The lowest data point was founded, and the average of the potential readings for all the values prior to the lowest point was calculated, taken into account getting rid of the data points that are far from the points in general. Furthermore, using the average I_0, the absorbance was calculated by the following equation.

Using elemental analysis to determine the percent mass composition of each element in a compound is the first step in creating an empirical formula. There are many different types of elemental analysis, but in this experiment gravitational analysis and Beer’s Law are used. Elemental analysis is first used to find the moles of each element, then converted to mass, and then the percent mass of the element in the product is found (2).

Found on Celebrity Airlines Flight 82181 were a number of substances brought on by passengers. Given that the crash was ruled a terrorist attack, identification of all substances found on and in the bodies and luggages of the victims needed to be made. To do this, empirical and molecular formulas were put into use when determining substance identities. Each substance was tested to find the percent composition of carbon, hydrogen, nitrogen, and oxygen, and then used to find the empirical formula of the substance by using 100 grams of each substance to represent 100% made up by the elements combined. The mass of each element in the substance calculated from the percent was then divided by the molar mass of that

We began this experiment by weighing out the known values of mass for 1-chloro-2,4-dinitrobenzene and m-aminobenzoic acid which was 1.012g and 0.686g respectively. These values were calculated before the experiement based on the mole ratios of the balanced equation in question. Here the reaction was a 1:1 ratio so we were able to determine the theoretical mass of our product, m-(2,4-dinitroanilino)

The primary goal of this laboratory is to correctly identify an unknown substance. To achieve this task, one may use various tests that reveal both chemical and physical properties of a substance. By comparing the results of a known substance and the unknown substance, one may eliminate alternative possibilities and more accurately predict the undisclosed compound. Furthermore, by performing these tests, data can be collected and verified regarding chemical and physical properties of the unknown. Understanding the chemical properties of a known substance aids one’s understanding of the unknown based on comparative analysis of the results of the tests.

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 guiding question of this ADI lab was, “What are the identities of the unknown compounds?” The goal of this lab was to understand the relationships between moles and molar mass to find the identity of unknown compounds. The mole can be used to measure small amounts of a substance or is used to convert from unit to unit using dimensional analysis. One mole is equivalent to the molar mass in grams of that substance. If you start with the moles of an unknown substance, multiply it by a given compound’s molar mass, and then divide it by however many moles are in the compound of your choice, you will get the mass of the compound. With that answer you can then compare with mass of the compound in the bag to determine its identity. We first started

Using the direct weighing and weighing by difference methods to find weight and mass of chemicals and compounds.