Ionic bonds polyatomic ions

NH4)2S04 is an ionic solid composed of covalently bonded polyatomic ions both obey the octet rule ... 

Distinguish between each of the following pairs (a) an ion and an ionic bond, (b) an ion and a free atom, (c) a covalent bond and an ionic bond, (cl) a triple bond and three single bonds on the same atom, (e) a polyatomic molecule and a polyatomic ion. 

The charges on polyatomic ions cause ionic bonding between these groups of atoms and oppositely charged ions. In writing electron dot structures, the distinction between ionic and covalent bonds must be clearly indicated. For example, an electron dot diagram for the compound NH4NO, would be... 

Ionic bonding results from electrostatic interactions between ions, which can be formed by the transfer of one or more electrons from a metal to a nonmetal or group of nonmetals (forming a polyatomic ion, like N03 ). Covalent bonding, on the other hand, results from sharing one or more electron pairs between two nonmetal atoms. 

This polyatomic ion (type AB6), like (c), does not obey the octet rule without modification since 12 electrons must be shared to form 6 Sb-F bonds. Sb is a 5 A element, but the charge on the ion gives an extra electron which participates in bonding. The Lewis formula predicts 6 electron groups around the central Sb atom and an octahedral electronic geometry. There are no lone pairs on the Sb atom, so the ionic geometry is the same as the electronic geometry (Section 8-12). 

Potassium is a metal, and the polyatomic anion, C104 is a nonmetal therefore, the compound is an ionic solid at room temperature. When the compound is dissolved in water, the ionic bond between the cation, K+, and the polyatomic anion, Cl()4, is broken due to the polarity of the water molecule, resulting in the two aqueous ions, K+ and C104 . 

Some ionic compounds contain a combination of bonds. For instance, in polyatomic ions such as ammonium (NH4+), the hydrogen atoms are bonded to the nitrogen atom by polar covalent bonds. The ionic bond is thus between this covalently bonded moiety and another oppositely charged ion such as chloride (CT). 

In Sections 9-3 and 9-4, we will show you two types of chemical bonds ionic and covalent. It is important to be able to represent compounds in terms of the atoms and valence electrons that make up the chemical species (compounds or polyatomic ions). One of the best ways is to use Lewis symbols and structures. 

Ionic bonding is present in compounds containing a metal and a nonmetal or in a compound containing one or more polyatomic ions. There are a few exceptions to this generalization, but these usually do not appear in this type of question. An ionic substance must contain at least two different elements, so we... 

Ionic bonding may also involve polyatomic ions. The polyatomic ion(s) simply replace(s) one or both of the monoatomic ions. 

Ionic bonds can also result from the interaction of polyatomic ions. 

Oxidation numbers are just a bookkeeping method used to keep track of electron transfers. In a covalent molecule or a polyatomic ion, the oxidation number of each element does not represent an ionic charge, because the elements are not present as ions. However, to assign oxidation numbers to the elements in a covalent molecule or polyatomic ion, you can pretendthe bonds are ionic. 

Sorry, it s true. Not only are polyatomic ions annoying because you have to memorize them, but they pop up everywhere. If you don t memorize the polyatomic ions, you ll waste time trying to figure out weird (and incorrect) covalent bonding cirrangements when what you re really dealing with is a straightforwcird ionic compound. Here are the common polyatomic ions in Table 22-1 (see Chapter 6 for more information on these ions). 

Ionic compounds consist of positive ions (cations) and negative ions (anions) hence, ionic compounds often consist of a metal and nonmetal. The electrostatic attraction between a cation and anion results in an ionic bond that results in compound formation. Binary ionic compounds form from two elements. Sodium chloride (NaCl) and sodium fluoride (NaF) are examples of binary ionic compounds. Three elements can form ternary ionic compounds. Ternary compounds result when polyatomic ions such as carbonate (C032 ), hydroxide (OH-), ammonium (NH4+), form compounds. For example, a calcium ion, Ca2+, combines with the carbonate ion to form the ternary ionic compound calcium carbonate, CaC03. Molecular compounds form discrete molecular units and often consist of a combination of two nonmetals. Compounds such as water (H20), carbon dioxide (C02), and nitric oxide (NO) represent simple binary molecular compounds. Ternary molecular compounds contain three elements. Glucose ( 12 ) is a ternary molecular compound. There are several distinct differences between ionic and molecular compounds, as summarized in Table 1.2. 

Ternary ionic compounds are ionic compounds containing one or more polyatomic ions. The possible combinations are a monatomic cation bonded to a polyatomic anion, a polyatomic cation bonded to a monatomic anion, or a polyatomic cation bonded to a polyatomic anion. There are additional rules that must be added to the rules in the previous section ... 

Solution The first two ions are single atom anions and are called sulfide and nitride. The next two are binary ionic compounds, calcium fluoride and potassium sulfide. The polyatomic ions hydroxide and sulfate are present in sodium hydroxide and sodium sulfate. Finally, the last two compounds are covalently bonded and are called sulfur trioxide and carbon tetrachloride. 

Polyatomic ions are held together by covalent bonds and are attracted to oppositely charged ions by ionic bonds. 

The adjective simple describes an ion formed from a single atom. A simple ion could also be called monatomic, which means one-atom. Just as the prefix mon- means one, the prefix poly- means many. The term polyatomic ion means a charged group of two or more bonded atoms that can be considered a single ion. A polyatomic ion as a whole forms ionic bonds in the same way that simple ions do. 

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