polyatomic ion

Examples of polyatomic ion in the following topics:

• Lewis Structures for Polyatomic Ions

  • Lewis structures for polyatomic ions are drawn by the same methods that we have already learned.
  • When counting electrons, negative ions should have extra electrons placed in their Lewis structures; positive ions should have fewer electrons than an uncharged molecule.
  • Negative ions follow the same procedure.
  • The chlorite ion, ClO2–, contains 19 (7 from the Cl and 6 from each of the two O atoms) +1 = 20 electrons.
  • The hypochlorite ion, ClO−, contains 13 + 1 = 14 electrons.

• Formulas of Ionic Compounds

  • Polyatomic ions are a set of covalently bonded atoms that have an overall charge, making them an ion.
  • For example, the hydroxide ion has the formula OH-1.
  • When creating ionic compounds with these polyatomic ions, treat them the same way as typical monatomic ions (only one atom).
  • The parentheses were used to indicate that OH was a polyatomic ion and came as a "package deal."
  • Parentheses are always used when the compound contains multiples of the polyatomic ion.

• Naming Acids and Bases

  • Any polyatomic ion with the suffix "-ate" uses the suffix "-ic" as an acid.
  • When you have a polyatomic ion with one more oxygen than the "-ate" ion, then your acid will have the prefix "per-" and the suffix "-ic."
  • For example, the chlorate ion is ClO3-.
  • With one fewer oxygen than the "-ate" ion, the acid will have the suffix "-ous."
  • Most strong bases contain hydroxide, a polyatomic ion.

• Ions

  • An ion consisting of a single atom is a monoatomic ion; an ion consisting of two or more atoms is referred to as a polyatomic ion.
  • Ions are highly reactive species.
  • These representations can be thought of as equivalent for monoatomic ions, but the Roman numerals cannot be applied to polyatomic ions.
  • Polyatomic and molecular ions can also be formed, generally by gaining or losing elemental ions, such as H+, in neutral molecules.
  • Polyatomic ions are generally very unstable and reactive.

• Naming Ionic Compounds

  • Usually, the positively charged portion consists of metal cations and the negatively charged portion is an anion or polyatomic ion.
  • But to be considered an ion, they must carry a positive or negative charge.
  • If either the cation or the anion was a polyatomic ion, the polyatomic ion name is used in the name of the overall compound.
  • The polyatomic ion name stays the same.
  • Since the net charge of the ionic compound must be zero, the Cu ion has a 2+ charge.

• Formulas of Ionic Compounds

  • Ionic formulas must satisfy the noble gas configurations for the constituent ions and the product compound must be electrically neutral.
  • If the anion is a polyatomic ion, its suffix can vary, but is typically either -ate or -ite,as in the cases of sodium phosphate and calcium nitrite, depending on the identity of the ion.
  • A lesson on writing formulas for binary ionic compounds as well as ionic compounds containing polyatomic ions.

• Electron Configuration of Cations and Anions

  • These charged atoms are known as ions.
  • Ionization is not limited to individual atoms; polyatomic ions can also be formed.
  • Polyatomic and molecular ions are often created by the addition or removal of elemental ions such as H+ in neutral molecules.
  • The two notations are therefore exchangeable for monatomic ions, but the Roman numerals cannot be applied to polyatomic ions.
  • However, it is possible to mix the notations for the individual metal center with a polyatomic complex, as demonstrated using the uranyl ion (UO2) as an example.

• Salts that Produce Basic Solutions

  • As such, salts are composed of cations (positively charged ions) and anions (negative ions), and in their unsolvated, solid forms, they are electrically neutral (without a net charge).
  • The component ions in a salt can be inorganic; examples include chloride (Cl−), the organic acetate (CH3COO−), and monatomic fluoride (F−), as well as polyatomic ions such as sulfate (SO42−).
  • The bicarbonate ion is the conjugate base of carbonic acid, a weak acid.
  • But because HCl is a strong acid, the Cl- ion is not basic in solution, and it isn't capable of deprotonating water.
  • Because the bicarbonate ion is the conjugate base of carbonic acid, a weak acid, sodium bicarbonate will yield a basic solution in water.

• Naming Coordination Compounds

  • The procedure for naming ionic compounds containing polyatomic ions is the same as that for naming simple ions.
  • Thus, CaCO3 is named calcium carbonate; (NH4)2HPO4, a compound with two polyatomic ions, is named ammonium hydrogen phosphate; and Pb2+ paired with SO42- (PbSO4) is named lead(II) sulfate.
  • When naming a complex ion, the ligands are named before the metal ion.
  • Write the name of the central atom/ion.
  • Tetrachloridonickelate(II) ion.

• Polyatomic Molecules

  • A polyatomic molecule is a single entity composed of at least three covalently-bonded atoms.
  • Polyatomic molecules are electrically neutral groups of three or more atoms held together by covalent bonds.
  • Molecules are distinguished from ions by their lack of electrical charge.