Conversions chemical formula

Some ionic compounds—such as NaCl (table salt) and NaHCOs (baking soda)— have common names, which are nicknames of sorts learned by familiarity. However, chemists have developed systematic names for different types of compounds including ionic ones. Even if you are not familiar with a compound, you can determine its systematic name from its chemical formula. Conversely, you can deduce the formula of a compound from its systematic name. 

Exact numbers, such as the stoichiometric coefficients in a chemical formula or reaction, and unit conversion factors, have an infinite number of significant figures. A mole of CaCb, for example, contains exactly two moles of chloride and one mole of calcium. In the equality... 

Two-Dimensional Representation of Chemical Structures. The lUPAC standardization of organic nomenclature allows automatic translation of a chemical s name into its chemical stmcture, or, conversely, the naming of a compound based on its stmcture. The chemical formula for a compound can be translated into its stmcture once a set of semantic rules for representation are estabUshed (26). The semantic rules and their appHcation have been described (27,28). The inverse problem, generating correct names from chemical stmctures, has been addressed (28) and explored for the specific case of naming condensed benzenoid hydrocarbons (29,30). 

Sometimes chemists have to analyze substances about which they know very little. A chemist may isolate an interesting molecule from a natural source, such as a plant or an insect. Under these conditions the chemical formula must be deduced from mass percentage data, without the help of an expected formula. A four-step procedure accomplishes this by using mass-mole conversions, the molar masses of the elements, and the fact that a chemical formula must contain integral numbers of atoms of each element. 

As with all calculations of chemical amounts, we must work with moles. Because grams are asked for, we must do a mole-mass conversion this requires the molar mass of the substance, which in turn requires that we know the chemical formula. 

C03-0042. Diagram the process for converting from the mass of a compound of a known chemical formula to the number of atoms of one of its constituent elements. Include all necessary equations and conversion factors. 

Polyarylenevinylene (PAV) expressed by the chemical formula of [-Ar-CH=CH-]n, where Ar is an arylene ring, is an attractive n-conjugated polymer family because of the following features (i) by the thermal conversion from polyelectrolyte or organic-solvent-soluble precursors, one can obtain the PAV films which have large third-order susceptibility and excellent optical quality, and (ii) the band gap can be adjusted by suitable selection of the arylene rings. 

Several aspects of the concept of theoretical heat recovery efficiency can be understood by considering an idealized conversion of coal to a secondary fuel having a high H/C ratio, such as methane. In the following discussion, it is assumed that the conversion reactions proceed to completion at a temperature of 15 C and a pressure of 1 atmosphere although, of course, this cannot be realized in practice. Coal is assumed to have the idealized chemical formula of C1Q Hg. 

Stoichiometry is the series of calculations on the basis of formulas and chemical equations and will be covered in Chapter 4. The use of conversion factors is common even when the relative proportions are not fixed by a chemical formula. Consider a silver alloy used for jewelry production. (Alloys are mixtures of metals and, as mixtures, may be produced in differing ratios of the metals.) A particular alloy contains 86 percent silver. Factors based on this composition, such as... 

Since the numbers of moles are necessary to write the chemical formula, we must perform a set of conversions from grams to moles. 

The first publication about the computer translation of chemical names was published by Garfield in 1961. In that article, he described the conversion of names into chemical formulas and initiated the path toward N2S algorithm development.45 Developments in 1967 at CAS provided internal procedures for the automatic conversion of CAS names into chemical diagrams.46 47 The first commercially available software program was CambridgeSoft s Name=Struct released in 1999,48 now patented,49 which was followed shortly by ACD/Labs ACD/Name to Structure product released in 2000.50 Two more commercial products are available Chemlnnovation s NameExpert51 and... 

The chemical formula for a compound gives the ratio of atoms of each element in the compound to atoms of every other element in the compound. It also gives the ratio of dozens of atoms of each element in the compound to dozens of atoms of every other element in the compound. Moreover, it gives the ratio of moles of atoms of each element in the compound to moles of atoms of every other element in the compound. For example, a given quantity of H2O has 2 mol of H atoms for every mole of O atoms, and a given quantity of CH4 has 1 mol of C atoms for every 4 mol of H atoms. The mole ratio from the formula can be used as a factor to convert from moles of any element in the formula to moles of any other element or to moles of the formula unit as a whole. In Figure 7.2, these additional conversions have been added to those already presented in Figure 7.1. 

The number of moles of an element in a mole of componnd can also be used to calculate the number of moles of the compound involved in a reaction. The ratio of the number of moles of an element within a compound to the number of moles of the compound is determined by the compound s chemical formula (Section 7.3). Thns, the snbscripts of the formula may be used to form conversion factors. 

The conversions of Sections 10.1 and 10.2 are extended in this section, using Avogadro s number, density, and chemical formulas (moles of one element per mole of any other substance). 

It is often helpful in mass-mole conversions to include the chemical formula in the dimensional equation, as illustrated above.)... 

The nitrite isomers of [Co(NH3)5N02] were studied by J0rgensen and Werner, who observed that there were two compounds of the same chemical formula but of different colors [Figure 9-19(c)]. A red form of low stability converted readily to a yellow form. The red form was thought to be the M—ONO nitrito isomer and the yellow form the M—NO2 nitro isomer, based on comparison with compounds of similar color. This conclusion was later confirmed, and kinetic and labeling experiments showed that conversion of one form to the other is strictly intramolecular, not a result of dis.so-ciation of the N02 ion followed by reattachment. In a more recent example, the stable O — N — Ru form of [Ru(NO)5(OH)] is in equilibrium with the metastable N—O—Ru form [Figure 9-19(d)]. 

The graphs are arranged by carbon number and chemical formula to provide ease of use. English units are used for the property values. For those involved in SI and metric usage, each graph displays a conversion factor to provide the SI and metric units. 

A low-temperature process for conversion of radioactive sodium salt wastes into solid, relatively insoluble, thermally stable sodium aluminosilicates is described. The reaction of the waste (in aqueous solution) with powdered clays such as kaolin, bentonite, halloysite, or dickite produces small crystals (0.5 /xm) of cancrinite. Salts, including radioactive ones, are trapped in the cancrinite crystal lattice. The approximate chemical formula of the cancrinite produced is 2(NaAlSi04) x salt y H2O, with X = 0.52 and y = 0.68 when the entrapped salt is NaNOa. The stoichiometry requires two moles of NaOH for each mole of cancrinite formed. 

Conversion factors such as the one just used for fluorine can he written for any element in a compound. The number of moles of the element that goes in the numerator of the conversion factor is the subscript for that element in the chemical formula. 

You are given the number of moles of AI2O3 and must determine the number of moles of AP+ ions. Use a conversion factor based on the chemical formula that relates moles of Al + ions to moles of AI2O3. Every mole of AI2O3 contains two moles of Al + ions. Thus, the answer should be two times the number of moles of AI2O3. 

The mass of your backpack is the sum of the mass of the pack plus the masses of the books, notebooks, pencils, lunch, and miscellaneous items you put into it. You could find its mass by determining the mass of each item separately and adding them together. Similarly, the mass of a mole of a compound equals the sum of the masses of every particle that makes up the compound. You know how to use the molar mass of an element as a conversion factor in calculations. You also know that a chemical formula indicates the number of moles of each element in a compound. With this information, you can now determine the molar mass of a compound. 

Example Problem 11-8 illustrated how to find the number of moles of a compound contained in a given mass. Now, you will learn how to calculate the number of representative particles—molecules or formula units—contained in a given mass and, in addition, the number of atoms or ions. Recall that no direct conversion is possible between mass and number of particles. You must first convert the given mass to moles by multiplying by the inverse of the molar mass. Then, you can convert moles to the number of representative particles by multiplying by Avogadro s number. To determine numbers of atoms or ions in a compound, you will need conversion factors that are ratios of the number of atoms or ions in the compound to one mole of compound. These are based on the chemical formula. Example Problem 11-9 provides practice in solving this type of problem. 

You are given 35.6 g AICI3 and must calculate the number of Al + ions, the number of Cl ions, and the mass in grams of one formula unit of AICI3. Molar mass, Avogadro s number, and ratios from the chemical formula are the necessary conversion factors. The ratio of AP+ ions to CE ions in the chemical formula Is 1 3. Therefore, the calculated numbers of ions should be in that ratio. The mass of one formula unit in grams should be an extremely small number. 

To calculate the number of AP+ and Cl ions, use the ratios from the chemical formula as conversion factors. 

So far, we have identified coordination compounds only by their chemical formulas, but names are also useful for many purposes. Some substances were named before their structures were known. Thus, K3[Fe(CN)g] was called potassium fer-ricyanide, and K4[Fe(CN)g] was potassium ferrocyanide [these are complexes of Fe (ferric) and Fe (ferrous) ions, respectively]. These older names are still used conversationally but systematic names are preferred to avoid ambiguity. The definitive source for the naming of inorganic compounds is Nomenclature of Inorganic Chemistry-IUPAC Recommendations 2005 (N. G. Connelly and T. Damhus, Sr., Eds. Royal Society of Chemistry, 2005). 

---