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Chemical formulation for 4º ESO bilingual students.

Writing Formulas for Covalent Compounds Certain rules apply to the way names of covalent compounds are written: • The more electropositive element (further left on the periodic table) is listed before the more electronegative element (further right on the periodic table) • The second element is given an -ide ending. • Prefixes are used to denote how many atoms of each element are present in the compound. Prefixes and Molecular Compound Names Nonmetals may combine in a variety of ratios, so it is important that the name of a molecular compound indicates how many atoms of each type of element are present in the compound. This is accomplished using prefixes. If there is only one atom of the first element, no prefix is used. It is customary to prefix the name of one atom of the second element with mono-. For example, CO is named carbon monoxide rather than carbon oxide. Examples of Covalent Compound Names SO2 - sulfur dioxide SF6 - sulfur hexafluoride CCl4 - carbon tetrachloride NI3 - nitrogen triiodide Molecular Compound Prefixes Number 1 2 3 4 5 6 7 8 9 10

Prefix monoditritetrapentahexaheptaoctanonadeca-

Ionic compounds consist of cations (positive ions) and anions (negative ions). The nomenclature, or naming, of ionic compounds is based on the names of the component ions. Here are the principal naming conventions for ionic compounds, along with examples to show how they are used:


Roman Numerals A Roman numeral in parentheses, followed by the name of the element, is used for elements that can form more than one positive ion. This is usually seen with metals. Fe2+ Iron (II) Fe3+ Iron (III) Cu+ Copper (I) Cu2+ Copper (II)

-ous and -ic Although Roman numerals are used to denote the ionic charge of cations, it is still common to see and use the endings -ous or -ic. These endings are added to the Latin name of the element (e.g., stannous/stannic for tin) to represent the ions with lesser or greater charge, respectively. The Roman numeral naming convention has wider appeal because many ions have more than two valences. Fe2+ Ferrous Fe3+ Ferric Cu+ Cuprous Cu2+ Cupric

-ide The -ide ending is added to the name of a monoatomic ion of an element. H- Hydride F- Fluoride O2- Oxide S2- Sulfide N3- Nitride P3- Phosphide

-ite and -ate Some polyatomic anions contain oxygen. These anions are called oxyanions. When an element forms two oxyanions, the one with less oxygen is given a name ending in -ite and the one with more oxgyen is given a name that ends in -ate. NO2- Nitrite NO3- Nitrate SO32- Sulfite SO42- Sulfate

hypo- and perIn the case where there is a series of four oxyanions, the hypo- and per- prefixes are used in conjunction with the -ite and -ate suffixes. The hypo- and per- prefixes indicate less oxygen and more oxygen, respectively. ClO- Hypochlorite ClO2- Chlorite ClO3- Chlorate ClO4- Perchlorate

Examples:


Aluminium oxide – Al2O3

Gold(III) oxide – Au2O3

Carbon dioxide – CO2

Nitrogen dioxide – NO2

Hydrogen peroxide – H2O2

Iron(III) oxide – Fe2O3

Hydrogen chloride – HCl

Hydrochloric acid – HCl

Hydrogen bromide – HBr

Hydrobromic acid – HBr

Lithium hydride – LiH

Calcium hydride – CaH2

Indium arsenide – InAs

Lead(II) iodide – PbI2

Manganese(II) chloride – MnCl2

Mercury(II) sulfide – HgS

Nickel(II) chloride – NiCl2

Phosphorus pentafluoride – PF5

Potassium chloride – KCl

Rubidium fluoride – RbF

Lithium hydroxide – LiOH

Calcium hydroxide – Ca(OH)2

Boric acid – H3BO3

Carbonic acid – H2CO3

Sulfuric acid – H2SO4

Sulfurous acid – H2SO3

Hypochlorous acid – HclO

Nitric acid – HNO3

Palladium(II) nitrate – Pd(NO3)2

Potassium carbonate – K2CO3

Potassium perchlorate – KClO4

Silver nitrate – AgNO3

Sodium chlorate – NaClO3

Zinc carbonate – ZnCO3

Barium sulfate – BaSO4

Beryllium sulfite – BeSO3

Calcium chlorate – Ca(ClO3)2

Copper(II) nitrate – Cu(NO3)2

Lead(II) nitrate – Pb(NO3)2

Lithium carbonate – Li2CO3

Formulación inglés  

Reglas de formulación de química inorgánica para estudiantes bilingües de 4º de ESO

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