Naming Ionic Compounds with Polyatomic Ions

Naming Ionic Compounds with Polyatomic Ions 

Ionic compounds that contain polyatomic ions are named in the same way used to name binary ionic compounds. Attention must be paid as to whether the cation is a metal that forms a single cation or multiple cations, and the name of the polyatomic ion is that given in the table. Note how these six ionic compounds are named  

NaHC03, sodium hydrogencarbonate FeS04, iron(II) sulfate (NH4)3P04, ammonium phosphate Ba(OH)2, barium hydroxide 

Analysis of four of these formulas shows how their names are obtained  

It is important to remember that numerical prefixes are not used in the names of ionic compounds. It would be incorrect to name (NH4)3P04 triammonium phosphate. The only time you would see a numerical prefix is if it is part of the name of a polyatomic ion, as in the d/hydrogenphosphate ion. 

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Naming Ionic Compounds with Polyatomic Ions... 

If you answered incorrectly, review The Polyatomic Ions, page 92, and Naming Ionic Compounds with Polyatomic Ions, page 96. 

Given a name or chemical formula, tell whether it represents a binary ionic compound, an ionic compound with polyatomic ion(s), a binary covalent compound, a binary acid, or an oxyacid. 

Convert between names and chemical formulas for binary ionic compounds, ionic compounds with polyatomic ion(s), binary covalent compounds, binary acids, and oxyacids. 

When naming ionic compounds containing polyatomic ions, we write the positive ion, usually a metal, first, and then we write the name of the polyatomic ion. It is important that you learn to recognize the polyatomic ion in the formula and name it correctly. As with other ionic compounds, no prefixes are used. 

Ionic compounds involving polyatomic ions follow the same basic rule Write the name of the metal first, and then simply add the name of the nonmetal (with the polyatomic anions, it is not necessary to add the -ide ending). 

In naming ionic compounds, it is important to recognize polyatomic ions and to determine the charge of cations with variable charge. 

The bonding between the atoms within polyatomic ions is just like the bonding within molecular compounds (Section 5.3), but the group of atoms has either more or fewer electrons than protons and therefore has an overall charge. Compounds that contain polyatomic ions are ionic, and their formulas are written by the same procedure described for binary ionic compounds. The only difference is that the polyatomic ion formula is enclosed in parentheses when more than one such ion is present. For example, the formula of aluminum nitrate is Al(NOg)g. The compounds are also named in the same manner as binary ionic compounds, with the... 

Solution Each compoimd is ionic and is named using the guidelines we have already discussed. In naming ionic compounds, it is important to recognize polyatomic ions and to determine the charge of cations with variable charge, (a) The cation in this compound is K", and the anion is S04. (If you thought the compound contained and... 

Table 4.5 gives examples of ionic compounds, including those with polyatomic ions and with elements showing variable oxidation states. These examples will allow you to deduce formulas and names from the ions present. 

Compounds containing polyatomic ions are named in the same manner as binary ionic compounds. The name of the cation is given first, followed by the name of the anion. For example, the two compounds formed with silver by the nitrate and nitrite anions are named silver nitrate, AgN03, and silver nitrite, A 02, respectively. When multiples of a polyatomic ion are present in a compound, the formula for the polyatomic ion is enclosed in parentheses. 

Chapter 6, Ionic and Molecular Compounds, describes how atoms form ionic and covalent bonds. Chemical formulas are written, and ionic compounds— including those with polyatomic ions—and molecular compounds are named. An introduction to the three-dimensional shape of carbon molecules provides a basis for the shape of organic and biochemical compounds. Organic chemistry is introduced with the properties of inorganic and organic compounds and condensed structural formulas of alkanes. Section 6.1 is now tilled Ions Transfer of Electrons, 6.2 is titled Writing Formulas for Ionic Compounds, 6.3 is... 

Polyatomic ions have fixed charges and can combine with ions of opposite charge to form ionic compounds. These compormds are named by writing the name of the positive ion first and then the name of the negative ion. 

This is an ionic compound in which the metal cation (K ) has only one charge. The correct name is potassium hypochlorite. Hypochlorite is a polyatomic ion with one less O atom than the chlorite ion, C102 . 

Name one ionic compound that contains a polyatomic cation and a polyatomic anion (see Table 2.3). Explain why ions with charges greater than 3 are seldom found in ionic compounds. 

Many ionic compounds contain anions with more than one atom. These ions are called polyatomic ions and are tabulated in Table 4-2. In naming compounds that contain these polyatomic ions, simply use the name of the polyatomic ion as the name of the anion. For example, KNO3 is named according to its cation, potassium, and its polyatomic anion, nitrate. The full name is as follows ... 

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