(Because of the huge variety of possible organic compounds [over six million, and counting], the rules for naming structures more complex than statisthe chain alkanes are much more sophisticated than those we`ve seen so far, but these rules will be discussed if you take organic chemistry.) A metal plus a polyatomic ion gives an ionic compound. In many cases, two elements can be combined in different ways to create completely different connections. (This cannot occur with ionic compounds, except in the case of metals that can form more than one charge.) For example, carbon can share electrons with one oxygen to form CO (carbon monoxide), or with two oxygens to form CO2 (carbon dioxide). For this reason, it is necessary to specify how many of each element are present in the connection. Remember the Supreme Directive in written formulas: Ca(OH)2 ¹ CaOH2! Going back to writing the formula, I find that the cross-method (aka cross-sectional method/rule) is best when it comes to writing a foolproof formula. I mean, who wouldn`t want to have the formula 100% correctly? So there you have it: metals combine with nonmetals to form ionic compounds. When naming binary ionic compounds, name the cation first (specifying the charge, if necessary), and then the nonmetallic anion (root element + -ide). Ionic compounds are compounds made up of ions, charged particles that form when an atom (or a group of atoms in the case of polyatomic ions) gains or loses electrons. Metals combine with polyatomic ions to form ionic compounds. First, name the cation (enter if necessary. the charge), then the polyatomic ion, as shown in the table above (or as derived from the given rules).

Acids are compounds in which the «cation» is H+. (These aren`t really ionic compounds, but more on that later.) These can be called compounds, as in the previous cases, for example HCl is «hydrogen chloride», but they are more often given special «acid names» (especially when dissolved in water, which is most often the case). The word «hydrogen» is omitted, the word «acid» is added at the end; The suffix is amended as follows: these elements normally form ionic compounds; Many of them can form more than one cation. (The charges of the base transition metals must be memorized; Group IV and V metal cations tend to be either the group number or the group number minus two.) Ionic compounds are (usually) formed when a metal reacts with a non-metal (or polyatomic ion). Covalent compounds are formed when two nonmetals react with each other. Since hydrogen is a nonmetal, binary compounds containing hydrogen are usually also covalent compounds. Organic chemistry has a completely different set of nomenclature rules; Straight-chain alkanes are named with a prefix and the suffix -ane. Note that after C4, the prefixes are the same as those listed above for binary covalent compounds. Acidic salts are ionic compounds that still contain acidic hydrogen, such as NaHSO4. When naming these salts, specify the number of acidic hydrogens in the salt.

For example, if you write formulas for compounds that contain polyatomic ions, you should use a list of common ions. You will usually get this list from your teacher. Ask which of the polyatomic ions you need to remember and if you can use the list of ions for a test. For ionic compounds, the term formula mass or formula weight is used instead, as no molecules are present. Covalent or molecular compounds form when elements share electrons in a covalent bond to form molecules. Molecular compounds are electrically neutral. Ferrous chloride or ferric chloride The cationic load must be specified because iron can form more than one filler. The mass of the molecule/formula is numerically equal to the mass of one mole of the substance. Polyatomic ions are ions consisting of two or more atoms connected by covalent bonds, but always have a net deficiency or excess of electrons, resulting in a total charge of the group. Alkanes contain only carbon-carbon single bonds and are the simplest hydrocarbons. Hydrocarbons contain only carbon and hydrogen and are the simplest type of organic compound (a compound that contains carbon). The mercury(I) cation is a special case; it consists of two Hg+ ions connected to each other and is therefore always in the form Hg22+.

(Therefore, mercury(I) chloride is Hg2Cl2, not HgCl, while mercury(II) chloride is HgCl2.) Content: Types of compounds Ion types: Main group metals (IA, IIA and IIIA) Transition (group B) and post-transition (groups IVA and VA) main group Nonmetals (IVA, VA, VIA and VIIA groups) Polyatomic ions Formulae for writing ionic compounds Nomenclature of ionic and covalent compounds 1. Binary ionic compounds containing a metal and a non-metal 2. Ionic compounds containing a metal and a polyatomic ion 3. Acids and acids Salts 4. Binary covalent compounds between two nonmetals 5. Hydrocarbons Molecular weights from chemical formulas Testimonials Molecular weight of H2O = (2 x atomic mass of H) + (1 x atomic mass of O) = (2 x 1.00797) + (1 x 15.9994) amu = 18.02 amu Metals of groups IA, IIA and IIIA tend to form cations by losing all their outermost electrons (valence). The load on the cation is the same as the group number. The cation has the same name as the neutral metal atom. [Important exception: if the compound contains oxygen and a halogen, the halogen is placed first. If both items belong to the same group, the item with the higher period number is named first.] This may be hard to imagine, so I`ll apply this method to five examples. Note that this method also works on polyatomic ions, but remember to use the bracket.

Nonmetals in the IVA, VA, VIA, and VIIA groups tend to form anions by gaining enough electrons to fill their valence shell with eight electrons. The charge on the anion is the group number minus eight. The anion is named by taking the root name of the element and adding the ending -ide. Adapted from McMurry/Fay, section 2.10, p. 2. 56-63 and Laboratory Manual 1411, pp. 27-31. (References) Alkanes have the general formula CnH2n + 2 and are the components of several important fuels such as natural gas and gasoline. A binary connection is a connection formed by two different elements. There may or may not be more than one element of each element.

A diatomic compound (or diatomic molecule) contains two atoms, which may or may not be identical. There are some regularities in the names of these polyatomic ions. George E. Shankle and Harold W. Peterson, Laboratory Manual of Chemistry 1411. Academic publication at Angelo State University, San Angelo, TX 76909, pp. 27-31. Do you want to test your skills? Each set of exercises consists of 10 questions – 5 on monatomic ions and 5 on polyatomic ions. (You can open the practice in another tab if you need the list of monatomic and polyatomic ions) Have fun crossing! Transition (group B) and post-transition (group IVA and VA) Metals Main group of nonmetals (IVA, VA, VIA and VIIA groups) The systematic names (also known as the parent system) of these ions are derived by naming the metal first, followed in parentheses by the charge written in Roman numerals.

For underlying metals, which usually form a single filler, it is usually not necessary to specify the charge in the compound name. Not binary (only one type of atom), but diatomic (two atoms) Two nonmetals combine to form a covalent or molecular compound (i.e. held together by covalent bonds resulting from the sharing of electrons). Do NOT use prefixes to indicate how many of each element there are. This information is included in the connection name. The molecular weight or molecular weight of a compound (measured in atomic mass units, amu) is obtained by adding the atomic masses of all atoms present in a unit of substance. For help memorizing polyatomic ions, watch this video. Many of these ions have common or trivial names formed from the root of the element name (in some cases the Latin name) and the ending -ic or -ous. (The -ic endings go with the highest possible load, the -ous endings go with the lowest possible load). For example, the molecular weight of water would be obtained by the following process: ions of certain transition metals and post-transition metals (groups IVA and VA) John McMurry and Robert C. Fay, Chemistry, 4th ed.

Upper Saddle River, NJ: Pearson / Prentice Hall, 2004, p. 56-63. The simplest alkanes are straight-chain alkanes, in which all carbon atoms are connected in a branchless line. (Nothing could be simpler!) Binary (two different elements) and diatomic (two atoms) The prefix bi- implies an acidic hydrogen: NaHCO3 is therefore sodium bicarbonate (or sodium bicarbonate); NaHSO3 is sodium bisulfite (or sodium hydrogen sulphite), etc.* Note, however, that nitrogen does not follow this pattern (i.e. nitrate, NO3-).