During this investigation the question we looked to answer was: what are the identities of the unknown compounds? In an effort to answer the question, our group designed a method in which the relationships between the unknown compounds in plastic bags were compared so that their identities could be determined. The mole (mol) provides a measure of the number of atoms present in the sample of a compound. One mole of an element or compound contains 6.022 x 1023 atoms or molecules. The molar mass (g/mol) refers to the total mass (g) of an element present in a single mole of an element. Through knowing the mass and molar mass of a compound, one can then determine the number of a moles in a specific compound. Each substance possesses a unique molar mass because the atoms of various elements contain different numbers of protons, neutrons, and electrons, therefore they each have different masses. Moreover, one can use physical properties, such as molar mass, to identify something that is unknown. To begin, we formulated a method in which each unknown substance and compound were compared to find their molar relationships. In the experiment we calculated the molar mass of every compound by determining the amount of moles per gram in each element using the periodic table and then added them together. We then …show more content…
When the bag of Unknown substance A was measured, its mass was determined to be 6.49 g, and the amount of moles given was 0.111 mol. Using our experimental method, we determined the molar mass of Sodium chloride was 58.44g/mol. When the mass of Unknown substance A (6.49 g) was divided by the molar mass of Sodium chloride (58.44 g/mol), the answer was 0.111, which was the exact amount of moles given for Unknown substance A. Thus, it was determined that Unknown A was Sodium chloride. The process was repeated and the conclusion of our data is as
The objective of this lab was first to convert the mass of a compound to the number of moles and number of molecules and then determine the concentration of salt and its component. The first thing we did was get the mass of an empty container by using a scale and it came out to be 16.87g. Next thing we did was pick a substance which in this case it was Potassium Chloride and placed it on the scale to get a total mass of 31.20g. The container the Potassium Chloride was in only had a mass of 16.87g which means that the mass of the substance was 14.33g. To convert the mass to the number of moles we took the amount of the substance 14.33g and divided it by the mass of Potassium Chloride 74.55g and figured out that the number of moles was 0.192.
The purpose of this experiment was to determine the pKa, Ka, and molar mass of an unknown acid (#14). The pKa was found to be 3.88, the Ka was found to be 1.318 x 10 -4, and the molar mass was found to be 171.9 g/mol.
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
In this experiment, we learned about stoichiometry, empirical formula, molecular formula, polyprotic acids and bases, metathesis reactions, and moles.
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
Since we obtain an unknown proportion of a mixture, it’s important to mention that a mixture is a result of a combination of two or more pure substances that do not react chemically. The physical properties of a mixture depend on its composition because the amounts of each substance making up a mixture can vary. By taking advantage of the unique physical properties of individual components within a mixture, it should be possible to separate a mixture into its components. Mixtures have the following fundamental properties:
One milliliter of 6.00-M phosphoric acid was placed into a 125-mL Erlenmeyer flask using a volumetric pipette. Using a slightly larger pipette, six milliliters of 3.00-M sodium hydroxide was transferred into a 50-mL beaker. Then a disposable pipette was used to slowly mix the sodium hydroxide into the phosphoric acid while the solution was swirled around. Then both the beaker and flask were rinsed with 2-mL of deionized water and set aside. A clean and dry evaporating dish was weighed with watch glass on a scale. Then the solution was poured into the dish and the watch glass was placed on top. The solution was then heated with a Bunsen burner to allow for the water to boil off to reveal a dry white solid. After the dish cooled to room temperature it was once again weighed and the new mass was recorded.
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
The purpose of this lab is to study some of the physical properties of two types of solids – ionic and molecular. The samples used are sodium chloride (ionic) and camphor (molecular). The physical properties studied are odour, hardness, melting point, solubility in water and solubility in 2-propanol. It is observed that some of the physical properties of sodium chloride are no odours, hard, a high melting point, soluble in water and insoluble in 2-propanol; some of the physical properties of camphor are a strong odour, soft, a low melting point, insoluble in water and soluble in 2-propanol. A few conclusions can be drawn from these
The purpose of this lab was to become familiar with the three different balances and two different methods used to find the weight and mass of chemicals and compounds in the ChemLab program. The lab was performed by using three different types of balances, and the direct weighing and weighing by difference methods.
Aim: To classify unknown substances according to their structure type and to observe how the structure of materials affects their uses.
Molar Mass is basically in grams per mole for example salt has a molar mass of 5.8g per mole. The mass of an element refers to 6.0221415x1023 molecules of the substance. Molar Mass helps us figure out how many grams per mole we need to do this project and it helps us know how much we need to put into the solution. If you don’t Find
Mass spectroscopy is a technique used to determine an unknown compound’s molecular weight and formula. Mass spectrum, a graph that compares relative intensity (% of Base Peak) to Mass to Charge ratio (m/z) is created when the direction of the molecule, which becomes ionized, changes in the magnetic field, allowing the detection of mass. Fragmentation also occurs during the process of mass spectrometry, creating negative and positive ions. However, mass spectrometry only identifies positive ions.
When analyzing a blood sample containing drugs, often a normal scale or balance cannot detect the mass of the drugs in the sample due to the small size of the sample. In that case, in order to properly determine the mass of a drug in a sample, it becomes necessary to utilize a mass spectrometer. A mass spectrometer can measure the mass of atomic-sized particles with great accuracy (Jeol, 2006). In forensic toxicology, mass spectrometry can provide scientists with the identity and quantity of a drug in a sample (Christopher Tilson, personal communication, March 19, 21016). Mass spectrometry serves as an exceptionally useful method in the field of forensic drug analysis, as its ability to determine the mass of exceedingly small particles assists in the classification and quantification of drugs in a sample.