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Other examples of compounds with ionic bonds are:
- Magnesium sulfate, MgSO 4
- Cesium Fluoride, CeF
- Potassium Cyanide, KCN
While other examples of covalent bonds are:
- Water , H2O
- Methane, CH4
- Ammonia, NH3
- Tin iodide, SnI 4
- Titanium(IV) chloride, TiCl 4
binary ionic compounds
Binary ionic compounds have two constituents, each of which is made up of a single element.
To learn to name binary ionic compounds, both partners in the compound must be monatomic, or they could be made up of multiple atoms respectively.
Metallic compounds with halides or oxygens are usually ionic solids, which have a crystal lattice in which cations and anions are bound, held together by electrostatic forces .
The cation, positively charged part is the one that ends the name of the compound. However, the specific naming conventions will vary between elemental groups.
The elements found within the first and second groups of the periodic table, alkaline and alkaline earth, form ions with a charge equal to their group number. This constant trend means that compounds containing one of these elements will simply have its name.
So the group one potassium ion always carries a charge equal to +1. The name of his compound would therefore always end with potassium. The same happens with group two of the periodic table, for example, compounds that contain the cation magnesium will have a charge of +2.
Many of the metals not in these two groups have the same charge, for example, aluminum, zinc, scandium, and silver usually have +3, +2, +3, and +1 charges respectively, and therefore , Roman numeral nomenclature is not used as other metals do.
Before writing the name of the cation, you can put the name of the monoatomic anion followed by the ending “-ide”. For example, the chemical formula for KCl would be the name for potassium chloride.
Naming the cations of the transition metals
The nomenclature can be a little more complicated, when the elements do not belong to groups one and two. Elements found between group three and twelve, called transition metals, lose different numbers of electrons depending on the situation. They form cations with different charges, generating unique compounds with different properties.
The charge of the transition metal cation is determined by equating the charge to the constituent anion of the compound.
To account for charge variations in transition metals, the Stock nomenclature is used. This method uses Roman numerals to indicate the charge of the cation in the compound. Numbers can be placed in parentheses with the word ion.
Fe 2+ and Fe 3+ are examples that can carry the +2 and +3 charge. If the anion carries charge -3, the cation will carry charge +3, the same would happen for the anion with charge -2 that the cation would carry charge +2. This can be clarified by saying that Fe(II) and Fe(III) are being used.
It must be emphasized again, that elements that form ions with a single charge need not be written this way. These methods disambiguate the use of fillers specifically around transition metal fillers.
The process for writing the anion in this case remains unchanged. For example, the compound CoCl 2 would be translated as “cobalt(II) chloride”, where the anion with the ending -ide is named first, followed by the cation of the transition element indicating the charge used with Roman numerals.
Other examples of ionic binary compounds are:
- Sodium chloride NaCl
- Zinc iodide ZnI 2
- Iron(III) chloride FeCl 3
Polyatomic ionic compounds
Polyatomic compounds have more than one type of atom. They can have a monatomic component and a polyatomic component, as exemplified by NaNO 3 , sodium nitrate. Or they could have two polyatomic components, as seen in (NH₄)₂SO₄, ammonium sulfate.
Polyatomic ionic compounds, although they may initially seem complex, but to name it, the anion is also written first followed by the cation. For example, NaNO 3 is called “sodium nitrate.” Sodium is named according to the same rules as above. But NO 3 , being its own compound, should be called “nitrate”. (NH₄)₂SO₄ contains two polyatomic ions, ammonium and sulfate. The combination of the cation and the anionic component gives “ammonium sulfate”.
Examples of polyatomic ionic compounds:
- Calcium carbonate CaCO 3
- Ammonium nitrate NH₄NO 3
- Potassium nitrate KNO3
- Iron(II) hydroxide Fe(OH) 2
- Sodium phosphate Na 3 PO 4
- Tin(IV) phosphate Sn 3 (PO 4 ) 4
You need to be familiar with polyatomic ions and cations, so it can be used when naming ionic compounds. A summary of the most common cations and anions is given below.
Polyatomic cations:
- Ammonium NH 4 +
- Hydronium H 3 O +
polyatomic anions:
- Nitrate NO 3 –
- Nitrite NO 2 –
- Hydroxide OH –
- Chlorate ClO 3 –
- Chlorite ClO 2 –
- Carbonate CO 3 2-
- Bicarbonate HCO 3 –
- CH3COO- acetate
- Sulfate SO 4 2-
- Sulfite SO 3 2-
- Phosphate PO 4 3-
- Phosphite PO 3 3-
- Cyanide CN-
- Oxalate C 2 O 4 2-
References
Crutchlow, C. (2021). Naming Ionic Compounds | ChemTalk. Retrieved 15 March 2022, from https://chemistrytalk.org/naming-ionic-compounds/
Ionic and Covalent Bonds. (2013). Retrieved 15 March 2022, from https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Fundamentals/Ionic_and_Covalent_Bonds
Properties of ionic compounds | Chemtube. (2022). Retrieved 15 March 2022, from https://www.quimitube.com/videos/propiedades-de-los-compuestos-ionicos/
