naming compounds unit 3

What are Binary compounds?

Compounds containing two elements (so called binary compounds) can either have ionic or covalent bonding

Molecular/Covalent compounds

the prefixes included in the name are all that are needed to write the formula

Naming Acid compounds

Acids will always include the (aq) symbol beside the formula, and the name will include the word acid. Acids 1. If the acid is H and another element (or a polyatomic ion not containing oxygen), a. Start with the prefix hydro- b. Name the second element, and change the ending to -ic c. Add the word Acid 2. If the acid is H and a polyatomic ion containing oxygen, a. Name the polyatomic ion and change the ending i. If the ion ends in -ate, change the ending to -ic ii. If the ion inds in -ite, change the ending to -ous b. Add the word Acid

How to tell if a compound is ionic or covalent(molecular)

If a compound is made from a metal and a non-metal, its bonding will be ionic. Ionic compounds do not use the prefixes di-, tri-, etc; if you see these, the compound must be molecular Ionic compounds will contain both metals and non-metals, or at least one polyatomic ion. If a compound is made from two non-metals, its bonding will be covalent. To decide if a binary compound has ionic or covalent bonding, first locate the two elements concerned in the Periodic Table and decide if they are metals or non-metals If they are both non-metals (such as carbon and oxygen) they will form a covalent compound (such as carbon dioxide, CO2). If one is a metal (like sodium) and the other a non-metal (like fluorine), they will form an ionic compound (such as sodium fluoride, NaF). exception for ammonium. ammonium (NH4+) Since ammonium is an ion, it forms ionic compounds. If the compound begins with H, it's an acid.

polyatomic ions

If the compound ends in -ate, -ite, etc., there must be a polyatomic ion, therefore the compound is ionic

Naming Binary ionic compounds

Ionic 1. Name the positive ion (metal or polyatomic) first 2. Name the negative ion (nonmetal or polyatomic) second. If the negative ion is a nonmetal, change the ending to -ide. DON'T change the ending of polyatomic ion names! Binary compounds (those containing only two elements) are named in the following way. *The metal will ALWAYS be first in the formula *the nonmetal will always be LAST in the formula NaCl CaO Ionic compounds are named as metal non-metalides, for example sodium chloride (NaCl) magnesium oxide (MgO) That is, the name of the metal followed by the name of the non-metal with its ending altered to be -ide. In this context, the -ide ending signifies a simple negative ion containing only the non-metal whose name appears in the prefix to the name. More examples are potassium fluoride (KF) sodium oxide (Na2O) calcium chloride (CaCl2).

Naming Binary covalent compounds

Molecular compounds will contain only non-metals. Molecular 1. Name each of the nonmetals, in the same order as the formula. 2. Add prefixes to tell how many atoms of each nonmetal are present. However, ONLY use the prefix mono- with oxygen, and only if it is the final element in the formula. Covalent compounds are named in a similar way, but a prefix is added to the name of the second non-metal to indicate how many atoms of this element are present in the compound. For example sulphur difluoride (SF2) phosphorus trichloride (PCl3) sulphur tetrafluoride (SF4) phosphorus pentachloride (PCl5) sulphur hexafluoride (SF6).

ionic Hydrates

Preffix and Roman numerals are uses Some compounds contain H2O in their structure. These compounds are called hydrates. This is different from (aq) because the H2O is part of the molecule (not just surrounding it). The H2O can usually be removed if heated. A dot separates water and a greek prefix indicates the # of H2O groups: e.g. CuSO4•5H2O is copper(II) sulfate pentahydrate.

Ionic Compounds with a Multivalent Metals

Some transitional metals are multivalent, meaning they have more than one ion form (possible charge). On the periodic table, the most common form of the ion is listed on top In the name of the compound, Roman numeral are used after the cation to indicate which ion was used. Example: What is the name for TiF4? titanium can be Ti4+ or Ti3+ Fluorine is F- From the ratio in the formula you can find out it is Ti4+ 1 Ti4+ ion & 4 F- ions Titanium (IV) fluoride