How to Calculate Mass Percent Composition of a Compound

How to Calculate Mass Percent Composition of a Compound Mass percent composition of a molecule shows the amount each element in a molecule contributes to the total molecular mass. Each elements contribution is expressed as a percentage of the whole. This step by step tutorial will show the method to determine the mass percent composition of a molecule. An ExampleWith Potassium Ferricyanide Calculate the mass percent composition of each element in a potassium ferricyanide, K3Fe(CN)6 molecule. The Solution Step 1: Find the atomic mass of each element in the molecule. The first step to finding mass percent is to find the atomic mass of each element in the molecule.K3Fe(CN)6 is made up of potassium (K), iron (Fe), carbon (C) and nitrogen (N).Using the periodic table:Atomic mass of K: 39.10 g/molAtomic mass of Fe: 55.85 g/molAtomic mass of C: 12.01 g/molAtomic mass of N: 14.01 g/mol​​ Step 2: Find the mass combination of each element. The second step is to determine the total mass combination of each element. Each molecule of KFe(CN)6 contains 3 K, 1 Fe, 6 C and 6 N atoms. Multiply these numbers by the atomic mass to get each elements mass contribution.Mass contribution of K 3 x 39.10 117.30 g/molMass contribution of Fe 1 x 55.85 55.85 g/molMass contribution of C 6 x 12.01 72.06 g/molMass contribution of N 6 x 14.01 84.06 g/mol​ Step 3: Find the total molecular mass of the molecule. The molecular mass is the sum of the mass contributions of each element. Simply add each mass contribution together to find the total.Molecular mass of K3Fe(CN)6 117.30 g/mol 55.85 g/mol 72.06 g/mol 84.06 g/molMolecular mass of K3Fe(CN)6 329.27 g/mol​ Step 4: Find the mass percent composition of each element. To find the mass percent composition of an element, divide the mass contribution of the element by the total molecular mass. This number must then be multiplied by 100% to be expressed as a percent.Mass percent composition of K mass contribution of K/molecular mass of K3Fe(CN)6 x 100%Mass percent composition of K 117.30 g/mol/329.27 g/mol x 100%Mass percent composition of K 0.3562 x 100%Mass percent composition of K 35.62%Mass percent composition of Fe mass contribution of Fe/molecular mass of K3Fe(CN)6 x 100%Mass percent composition of Fe 55.85 g/mol/329.27 g/mol x 100%Mass percent composition of Fe 0.1696 x 100%Mass percent composition of Fe 16.96%Mass percent composition of C mass contribution of C/molecular mass of K3Fe(CN)6 x 100%Mass percent composition of C 72.06 g/mol/329.27 g/mol x 100%Mass percent composition of C 0.2188 x 100%Mass percent composition of C 21.88%Mass percent composition of N mass contribution of N/molecular mass of K3Fe(CN)6 x 100%Mass percent composition of N 84.06 g/mol/329.27 g/mol x 100%Mass percent composition of N 0.2553 x 100%Mass percent composition of N 25.53%​ The Answer K3Fe(CN)6 is 35.62% potassium, 16.96% iron, 21.88% carbon and 25.53% nitrogen.It is always a good idea to check your work. If you add up all the mass percent compositions, you should get 100%.35.62% 16.96% 21.88% 25.53% 99.99%Where is the other .01%? This example illustrates the effects of significant figures and rounding errors. This example used two significant figures past the decimal point. This allows for an error on the order of  ±0.01. This examples answer is within these tolerances.

The Aztec Calendar Stone - Not a Calendar After All

The Aztec Calendar Stone - Not a Calendar After All The Aztec Calendar Stone, better known in the archaeological literature as the Aztec Sun Stone (Piedra del Sol in Spanish), is an enormous basalt disk covered with hieroglyphic carvings of calendar signs and other images referring to the Aztec creation myth. The stone, currently on display at the National Museum of Anthropology (INAH) in Mexico City, measures about 3.6 meters (11.8 feet) in diameter, is about 1.2 m (3.9 ft) thick and weighs more than 21,000 kilograms (58,000 pounds or 24 tons). Aztec Sun Stone Origins and Religious Meaning The so-called Aztec Calendar Stone was not a calendar, but most likely a ceremonial container or altar linked to the Aztec sun god, Tonatiuh, and festivities dedicated to him. At its center is what is typically interpreted as the image of the god Tonatiuh, within the sign Ollin, which means movement and represents the last of the Aztec cosmological eras, the Fifth Sun. Tonatiuhs hands are depicted as claws holding a human heart, and his tongue is represented by a flint or obsidian knife, which indicates that a sacrifice was required so that the sun would continue its movement in the sky. At Tonatiuhs sides are four boxes with the symbols of the preceding eras, or suns, along with the four directional signs. Tonatiuhs image is surrounded by a broad band or ring containing calendrical and cosmological symbols. This band contains the signs of the 20 days of the Aztec sacred calendar, called Tonalpohualli, which, combined with 13 numbers, made up the sacred 260-day year. A second outer ring has a set of boxes each containing five dots, representing the five-day Aztec week, as well as triangular signs probably representing sun rays. Finally, the sides of the disk are carved with two fire serpents which transport the sun god in his daily passage through the sky. Aztec Sun Stone Political Meaning The Aztec sun stone was dedicated to Motecuhzoma II and was likely carved during his reign, 1502-1520. A sign representing the date 13 Acatl, 13 Reed, is visible on the surface of the stone. This date corresponds to the year 1479 AD, which, according to archaeologist Emily Umberger is an anniversary date of a politically crucial event: the birth of the sun and the rebirth of Huitzilopochtli as the sun. The political message for those who saw the stone was clear: this was an important year of rebirth for the Aztec empire, and the emperors right to rule comes directly from the Sun God and is embedded with the sacred power of time, directionality, and sacrifice. Archaeologists Elizabeth Hill Boone and Rachel Collins (2013) focused on the two bands which frame a conquest scene over 11 enemy forces of the Aztecs. These bands include serial and repeating motifs that appear elsewhere in Aztec art (crossed bones, heart skull, bundles of kindling, etc.) which represent death, sacrifice, and offerings. They suggest that the motifs represent petroglyphic prayers or exhortations advertising the success of the Aztec armies, recitations of which might have been part of the ceremonies which took place on and around the Sun Stone. Alternative Interpretations Although the most prevalent interpretation of the image on the Sun Stone is that of Totoniah, others have been proposed. In the 1970s, a few archaeologists suggested that the face was not Totoniahs but rather that of the animate earth Tlateuchtli, or perhaps the face of the night sun Yohualteuctli. Neither of these suggestions has been accepted by the majority of Aztec scholars. American epigrapher and archaeologist David Stuart, who typically specializes in Maya hieroglyphs, has suggested that it may well be a deified image of the Mexica ruler Motecuhzoma II. A hieroglyph at the top of the stone names Motecuhzoma II, interpreted by most scholars as a dedicatory inscription to the ruler who commissioned the artifact. Stuart notes that there are other Aztec representations of ruling kings in the guise of gods, and he suggests that the central face is a fused image of both Motecuhzoma and his patron deity Huitzilopochtli. History of the Aztec Sun Stone Scholars surmise that the basalt was quarried somewhere in the southern basin of Mexico, at least 18-22 kilometers (10-12 miles) south of Tenochtitlan. After its carving, the stone must have been located in the ceremonial precinct of Tenochtitln, laid horizontally and likely near where ritual human sacrifices took place. Scholars suggest that it may have been used as an eagle vessel, a repository for human hearts (quauhxicalli), or as a base for the final sacrifice of a gladiatorial combatant (temalacatl). After the  conquest, the Spanish moved the stone a few hundred meters south of the precinct, in a position facing upward and near the Templo Mayor and the Viceregal Palace. Sometime between 1551-1572, the religious officials in Mexico City decided the image was a bad influence on their citizens, and the stone was buried facing down, hidden within the sacred precinct of Mexico-Tenochtitlan. Rediscovery The Sun Stone was rediscovered in December 1790, by workmen who conducted leveling and repaving work on Mexico Citys main plaza. The stone was pulled to a vertical position, where it was first examined by archaeologists. It stayed there for six months exposed to the weather, until June of 1792, when it was moved into the cathedral. In 1885, the disk was moved to the early Museo Nacional, where it was held in the monolithic gallerythat journey was said to have required 15 days and 600 pesos. In 1964 it was transferred to the new Museo Nacional de Anthropologia in Chapultepec Park, that journey only taking 1 hour, 15 minutes. Today it is displayed on the ground floor of the National Museum of Anthropology, in Mexico City, within the Aztec/Mexica exhibition room. Edited and updated by  K. Kris Hirst. Sources: Berdan FF. 2014. Aztec Archaeology and Ethnohistory. New York: Cambridge University Press. Boone EH, and Collins R. 2013. The Petroglyphic Prayers on the . Ancient Mesoamerica 24(02):225-241.un Stone of Motecuhzoma IlhuicaminaS Smith ME. 2013. The Aztecs. Oxford: Wiley-Blackwell. Stuart D. 2016. The Face of the Calendar Stone: A New Interpretation. Maya Decipherment: June 13, 2016. Umberger E. 2007. Art History and the Aztec Empire: Dealing With the Evidence of Sculptures. Revista Espaà ±ola de Antropologà ­a American 37:165-202 Van Tuerenhout DR. 2005. The Aztecs. New Perspectives. Santa Barbara, CA: ABC-CLIO Inc.

Basic Macro and Microeconomic Policies Assignment

Basic Macro and Microeconomic Policies - Assignment Example Cost extravagances in the airline industry had brought financial costs up decreasing profits but did not automatically mean an increase in sales. Accounting problems and financial data were overlooked or neglected during the dot-com bust. First, too much money was spent on advertising which focused on selling and not marketing. Second, too much advertising money could have been saved if ads were focused on market segments. Cost extravagances in the airline industry had brought financial costs up decreasing profits but did not automatically mean an increase in sales. First, too much money was spent on advertising which focused on selling and not marketing in both online and offline advertising(Churchill,1995). The prior selling attitude of companies as the strove to increase net profits had been to prioritize the seller’s aim to generate profits. The sad thing about this is that the customers’ needs and wants were put to second place or just simply not taken up. Thus, mo ney was spent paying computer programmers large sums of money to make websites that would catch the eyes of prospective computer users. To prove that this type of strategy to increase sales was effective, the companies targeted all computers users whether they were inside the United States or in the United Kingdom or elsewhere. Unfortunately, there is no logic that increased advertising on the internet will automatically translate to increased sales.