The polyatomic ions NH 4 + and NO 3 − form NH 4NO 3 (ammonium nitrate), which is a widely used fertilizer and, in the wrong hands, an explosive. Similarly, Ca 2+ and SO 4 2− form CaSO 4 (calcium sulfate), which combines with varying amounts of water to form gypsum and plaster of Paris. Thus K + and NO 3 − ions combine in a 1:1 ratio to form KNO 3 (potassium nitrate or saltpeter), a major ingredient in black gunpowder. The overall charge on the cations must balance the overall charge on the anions in the formula unit. The method we used to predict the empirical formulas for ionic compounds that contain monatomic ions can also be used for compounds that contain polyatomic ions. Table 2.4 Common Polyatomic Ions and Their Names Formula Similarly, the formula for the ionic compound that contains Na + and O 2− ions is Na 2O. In the case of Mg 2+ and Cl −, for example, two Cl − ions are needed to balance the two positive charges on each Mg 2+ ion, giving an empirical formula of MgCl 2. If the charges are not the same magnitude, then a cation:anion ratio other than 1:1 is needed to produce a neutral compound. If the cation and the anion have charges of equal magnitude, such as Na + and Cl −, then the compound must have a 1:1 ratio of cations to anions, and the empirical formula must be NaCl. Consequently, the positive and negative charges in a formula unit must exactly cancel each other. All compounds, whether ionic or covalent, must be electrically neutral. Butane, for example, has the empirical formula C 2H 5, but it contains two C 2H 5 formula units, giving a molecular formula of C 4H 10.īecause ionic compounds do not contain discrete molecules, empirical formulas are used to indicate their compositions. is the absolute grouping of atoms or ions represented by the empirical formula of a compound, either ionic or covalent. The formula unit The absolute grouping of atoms or ions represented by the empirical formula.
The empirical formula for butane is therefore C 2H 5. The ratio of carbon atoms to hydrogen atoms in butane is 4:10, which can be reduced to 2:5. The molecular formula for butane is C 4H 10. The difference between empirical and molecular formulas can be illustrated with butane, a covalent compound used as the fuel in disposable lighters. Because the empirical formula is based on experimental measurements of the numbers of atoms in a sample of the compound, it shows only the ratios of the numbers of the elements present. In such cases, they usually begin by determining its empirical formula A formula for a compound that consists of the atomic symbol for each component element accompanied by a subscript indicating the relative number of atoms of that element in the compound, reduced to the smallest whole numbers., the relative numbers of atoms of the elements in a compound, reduced to the smallest whole numbers. When chemists synthesize a new compound, they may not yet know its molecular or structural formula. To describe the composition of a chemical compound.
DIMETHYL SULFIDE CHARGE ZIP FILE
zip file containing this book to use offline, simply click here.
DIMETHYL SULFIDE CHARGE DOWNLOAD
You can browse or download additional books there. More information is available on this project's attribution page.įor more information on the source of this book, or why it is available for free, please see the project's home page. Additionally, per the publisher's request, their name has been removed in some passages. However, the publisher has asked for the customary Creative Commons attribution to the original publisher, authors, title, and book URI to be removed. Normally, the author and publisher would be credited here. This content was accessible as of December 29, 2012, and it was downloaded then by Andy Schmitz in an effort to preserve the availability of this book.
DIMETHYL SULFIDE CHARGE LICENSE
See the license for more details, but that basically means you can share this book as long as you credit the author (but see below), don't make money from it, and do make it available to everyone else under the same terms. This book is licensed under a Creative Commons by-nc-sa 3.0 license.
0 kommentar(er)
