Nomenclature of Simple Compounds

Nomenclature of Simple Compounds A. Nomenclature of Binary Compounds Binary compounds are compounds that consist of only two types of elements, for example water (H2 O), ammonia (NH3 ), and methane (CH4 ). 1. Compound Formulas The elements that come first in the following order are written in front. B – Si – C – S – As – P – N – H – S – I – Br – Cl – O – F The chemical formula for ammonia is commonly written as NH3 instead of H3 N and the chemical formula for water is commonly written as H2 O instead of OH2 . 2. Name of Compound The names of the binary compounds of the two non-metals are concatenation names both types of elements with the suffix ida in the name of the second element. For example: • HCl = hydrogen chloride • H2 S = hydrogen sulfide If the combined elements form more than one type of compound, the compounds are distinguished by mentioning the index number in Greek as follows. 1 = mono 2 = di 3 = tri 4 = tetra 5 = penta 6 = hexa 7 = hepta 8 = octa 9 = nona 10 = deca Index one doesn't need to be mentioned, except for carbon monoxide. Examples: • CO = carbon monoxide (the mono prefix for C is not necessary) • CO2 = carbon dioxide • N2 O = nitrous oxide • NO = nitrogen oxides • N2 O3 = dinitrogen trioxide • N2 O4 = dinitrogen tetraoxide • N2 O5 = dinitrogen pentaoxide • CS2 = carbon disulfide • CCl4 = carbon tetrachloride c. Common Compounds Well-known compounds do not need to follow the rules in on. Example: • H2 O = water • NH3 = ammonia • CH4 = methane Individual Task 2 1. Write the names of the following compounds. a. CO b. CO2 c. SiCl4 d.Cl2O e. Cl2 O5 f. PCl5 g. SCl6 h.SO2 i. CBR4 j.ClF3 2. 2. Write the molecular formula of the compound having the following names. a. Phosphorus trichloride b. Carbon tetrachloride c. Dinitrogen trioxide d. silicon dioxide e.Dichlorine trioxide B. Nomenclature of Ionic Compounds Ionic compounds consist of a cation and an anion. The cation is generally a metal ion, while the anion can be a non-metal anion or a polyatomic anion. A list of important cations and anions is given in Tables 3.1 and 3.2. 1. Compound Formulas The metal element is written on the front. For example, the chemical formula for sodium chloride is written NaCl instead of ClNa. Ionic compound formula: b Xa+ + a Yb– ÿÿÿ Xb Yes For a and b equal to number 1 there is no need to write. The formula for an ionic compound is determined by the ratio of the charges of the cation to that of the anion. The number of positive charges is equal to the number of negative charges. Example: • Na+ + Cl– NaCl • 2 Na+ + SO4 2– Na2 SO4 • Fe2+ + 2 Cl– FeCl2 • Al3+ + PO43AlPO4 2+ 2• Mg + CO3 MgCO3 + 3+ • 3 K + AsO4 K3 AsO4 sodium chloride sodium sulfate iron(II) chloride aluminum phosphate magnesium carbonate potassium arsenate 2. Name of Ionic Compound The name of an ionic compound is a combination of the name of the cation (in front) and the name of the anion (behind), the index number is not mentioned. Example • NaCl • CaCl2 • Na2 SO4 • Al(NO3 )3 = sodium chloride = calcium chloride = sodium sulfate = aluminum nitrate If a metallic element has more than one type of oxidation number, then the compounds are distinguished by writing the oxidation number, which is written in parentheses with Roman numerals after the name of the metal element. Example: • Cu2 O • CuO • FeCl2 • FeCl3 • Fe2 S3 • SnO • SnO2 = copper(I) oxide = copper(II) oxide = iron(II) chloride = iron(III) chloride = iron(III) sulfide = tin(II) ) oxide = tin(IV) oxide Individual Task 2 1. Write the names of the following compounds. a. Na2O b. ZnS c. d. e. f. g. h. i. j. MgO SnCl2 Al2S3 Hg2Cl2 Ag2O K2Cr2O7 CuSO4 KMnO4