Chemical Names and Formulas PDF

Chemical Names and Formulas What is a Molecule? - is an electrically neutral group of two or more atoms held together by chemical bonds. What is Ions? - is an atom or a group of atoms having a positive and negative charge. CATION ANION are negative ions that are fo...

Chemical Names and Formulas What is a Molecule? - is an electrically neutral group of two or more atoms held together by chemical bonds. What is Ions? - is an atom or a group of atoms having a positive and negative charge. CATION ANION are negative ions that are formed when a nonmetal atom gains one or more electrons. Chemical Formulas is a symbolic expression of a compound or substance. It is also defined as shorthand of expressing the types and the number of atoms in a substance. Chemical Name is a set of rules to generate systematic names for chemical compounds. Types of Chemical Formula 1. Molecular Formula - gives the exact amount of each element present in the smallest unit of a substance. 2. Empirical Formula - show which elements are present and in what ratio they exist in the substance. 3. Structural Formula - used to represent the bonds between molecules Chemical Formulas and Chemical Name Ionic Compounds - Combination of cation and anion atoms. Steps in Naming the Ionic Compounds (Binary) 1. Determine the chemical name involved. 2. Change the suffix into -ide of the second element. EXAMPLE: NaCl Sodium Chloride AlF₃ Aluminum Flouride Sr₃N₂ Strontium Nitride BaS Barium Sulfide MgBr₂ Magnesium Bromide Steps in Naming the Ionic Compounds (Ternary) 1. Determine the chemical name involved. 2. The polyatomic ions will have a suffix of -ate. 3. Those metal elements can form more than one cation, the charged of cation must be written in Roman Numeral and enclosed in parentheses. And the suffix will be -ide. EXAMPLE: Li₂SO₄ Lithium Sulfate Na₂CO₃ Sodium Carbonate NH₄NO₃ Ammonium Nitrate FeCl₂ Iron (II) Chloride FeCl₃ Iron (III) Chloride Steps in Writing the formula of the Ionic Compounds 1. Determine the symbols for the atoms in a compound 2. Determine the forming ion (charge) in compound. 3. Criss-Cross multiply the charge 4. Remove the plus and negative sign to determine the chemical formula 5. All radicals take more than once (the subscript is 2 or more) must be enclosed in parentheses. EXAMPLE: Aluminum Sulfide Iron (II) Sulfate Al⁺³ S ⁻² Fe⁺² -² SO₄ Al₂S₃ FeSO₄ Chemical Formulas and Chemical Name Covalent Compounds - Combination of two or more non-metal elements Steps in Naming the Covalent Compounds 1. Write the name for both elements. 2. Change the ending of the second element to ide. 3. Place prefixes in front of each element based on the number of atoms present. 4. The prefix 'mono' is only used on the second non-metal in the chemical formula. 5. There shouldn't be two vowels in a row. For example, when you have 'mono' in front of 'oxide' it is written 'monoxide', not 'monooxide'. Prefixes: Mono - 1 atom Hexa - 6 atoms Di - 2 atoms Hepta - 7 atoms Tri - 3 atoms Octa - 8 atoms Tetra - 4 atoms Nona - 9 atoms Penta - 5 atoms Deca - 10 atoms EXAMPLE: N₂O₄ Dinitrogen Tetroxide CBr₃ Carbon Tribromide NO Nitrogen Monoxide OF₂ Oxygen Difluoride PCl₃ Phosphorus Trichloride Steps in Writing the formula of the Covalent Compounds 1. Look at the first word of the compound's name. Identify the element name. Write the symbol for this element. 2. If the first name of the compound has a prefix, write the number the prefix refers to as the symbol’s subscript. 3. Look at the second word in the compound's name and identify the element. Only the root of the element's name is used so the ending will be different. Write the symbol for the element referred to. 4. Determine the number that the prefix of the second name refers to and write this number after the second symbol as a subscript. EXAMPLE: Covalent Compounds Pentaphosphorus Tribromide Disulfur Tetrafluoride P₅ Br ₃ S₂ F ₄ Chemical Formulas and Chemical Name Acids - is a substance that donates protons or accepts a pair of valence electrons to form a bond Steps in Naming the Binary and Ternary Acids 1. In binary acid, the name always begin with prefix of “hydro” 2. Then add the root name of the second element (the non-metal) 3. Change the suffix -ic then word “acid” 4. In ternary acid, there’s no prefix. 5. Use the root of the name of polyatomic anion 6. If the name of the polyatomic ion ends with -ate, change it to -ic. 7. And f the name of the polyatomic ion ends with -ite, change it to -ous. Then the word “acid” EXAMPLE: HCl Hydrochloric acid HBr Hydrobromic acid H₂SO₃ Sulfurous acid H₂CO₃ Carbonic acid Steps in Writing the formula of the Acids Compounds 1. Determine the symbols for the atoms in a compound 2. Determine the forming ion (charge) in compound. 3. Criss-Cross multiply the charge 4. Remove the plus and negative sign to determine the chemical formula EXAMPLE: Hydrophosphoric Nitric acid acid H ⁺¹ P ⁻³ H ⁺¹ -1 NO₃ H₃P HNO₃ Chemical Formulas and Chemical Name Bases - is a substance that can neutralize the acid by reacting with hydrogen ions. Steps in Naming the Bases 1. Write the metal element FIRST 2. Then add hydroxide to name OH- group EXAMPLE: NaOH Sodium hydroxide RbOH Rubidium hydroxide MgOH₂ Magnesium hydroxide ZnOH₂ Zinc (II) hydroxide Steps in Writing the formula of the Base Compounds 1. Write the symbol for cation first 2. Write the formula for hydroxide ion 3. Criss-Cross multiply the charge 4. Remove the plus and negative sign to determine the chemical formula EXAMPLE: Calcium hydroxide Copper (II) hydroxide Ca⁺² OH⁻¹ Cu⁺² OH ⁻¹ CaOH₂ CuOH₂