01 Chemical Writing.pdf

FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Chemical Writing Lab Mod...

FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Chemical Writing Lab Module 1 Far Eastern University IAS – Dept. of Mathematics Biochemistry Cluster 1 Outline Chemical Formulas & Nomenclature Ionic Compounds Binary Covalent Compounds Chemical Equation Writing 2 1 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Chemical Formulas & Nomenclature 3 Ionic Compounds Ionic compounds are compounds made up of ions that are formed when atoms donate and receive electrons. The transfer of electrons lead to positive and negative charges (ions) that attract each and form an ionic bond. Cations – positively-charged atoms or molecules Anions – negatively-charged atoms or molecules Naming ionic compounds is usually based on the cation’s name followed by the anion’s name. 4 2 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Ionic Compounds Types of Ionic compounds 1. Binary ionic compounds – ionic compounds formed from just two elements and commonly ends with the suffix –ide 2. Ternary compounds – ionic compounds formed from a combination of more than two elements. They have variety of suffixes other than -ide 5 Rules in Naming Cations Cations formed from metal atoms bears the name of the metal itself. Ion Name 𝐾! Potassium ion 𝑁𝑎! Sodium ion 𝐶𝑎"! Calcium ion 𝑀𝑔"! Magnesium ion 6 3 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Rules in Naming Cations Some metal ions can have more than one charge such as those in the transition metals. We name them as the name of the metal itself and a Roman numeral enclosed in parenthesis to indicate the charge. Ion Name 𝐹𝑒 "! Iron (II) ion 𝐹𝑒 #! Iron (III) ion 𝐶𝑢! Copper (I) ion 𝐶𝑢"! Copper (II) ion 7 Rules in Naming Cations Usually, metals with two charges only can be named using their root Latin name / old metal name followed by the suffix –ous and –ic. The suffix –ous indicates the ion with the lowest charge, while –ic indicates highest. Ion Name Old Name Suffix 𝐹𝑒 "! Ferrous ion Latin: Ferrum -ous for +2 charge 𝐹𝑒 #! Ferric ion Latin: Ferrum -ic for +3 charge 𝐶𝑢! Cuprous ion Latin: Cuprum -ous for +1 charge 𝐶𝑢"! Cupric ion Latin: Cuprum -ic for +2 charge 8 4 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Rules in Naming Cations Cations formed from nonmetal atoms have the suffix –ium There are only two of them Ion Name Derived from 𝐻! Hydronium ion Hydrogen (𝐻) atom 𝑁𝐻$! Ammonium ion Ammonia (𝑁𝐻#) 9 Rules in Naming Anions Monoatomic anions will have the suffix -ide Ion Name 𝐻% Hydride ion 𝑂"% Oxide ion 𝐶𝑙% Chloride ion 𝐵𝑟 % Bromide ion 10 5 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Rules in Naming Anions Polyatomic anions with oxygens are called oxyanions. They usually bear the suffix – ate for the common oxyanion, and –ite if is one oxygen less than the common. Ion Name Suffix 𝑁𝑂#% Nitrate ion -ate since it is the common 𝑁𝑂"% Nitrite ion -ite since it is one O less than common 𝑆𝑂$"% Sulfate ion -ate since it is the common 𝑆𝑂#"% Sulfite ion -ite since it is one O less than common 11 Rules in Naming Anions The following are the common oxyanions that you have to remember Ion Name Note 𝐶𝑂#"% Carbonate ion Does not have –ite counterpart 𝑁𝑂#% Nitrate ion 𝑃𝑂$#% Phosphate ion 𝑆𝑂$"% Sulfate ion 𝐶𝑙𝑂#% Chlorate ion Extendable up to four versions 12 6 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Rules in Naming Anions Some oxyanions can be extended to form four members. We add prefix per- to the oxyanion with one oxygen more than the common, and prefix hypo- to the oxyanion that is one oxygen less to that of the –ite version. Ion Name Note 𝐶𝑙𝑂$% Perchlorate ion One oxygen more than common 𝐶𝑙𝑂#% Chlorate ion Common oxyanion 𝐶𝑙𝑂"% Chlorite ion One oxygen less than common 𝐶𝑙𝑂% Hypochlorite ion One oxygen less than -ite 13 Rules in Naming Anions Anions derived by adding 𝐻 1 to an oxyanion are named by adding as a prefix the word hydrogen/bi- or dihydrogen 𝐶𝑂!"# + 𝐻$ → 𝐻𝐶𝑂!# carbonate hydrogen carbonate bicarbonate 𝑃𝑂%!# + 𝐻$ → 𝐻𝑃𝑂%"# + 𝐻$ → 𝐻" 𝑃𝑂%# phosphate hydrogen phosphate dihydrogen phosphate biphosphate 14 7 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Summary You must remember the names of the anions and cations in Chemistry. Just simply follow the rules or use the table beside and use it as your memory guide. 15 Formula of Ionic Compounds Since we now know the names of ions, we can now make ionic compounds. Ionic compounds are made by combining cations and anions in right proportion so there would be no charge in its final form. The right proportion of cations and anions can be easily obtained by crisscrossing their number of their charges. 16 8 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Formula of Ionic Compounds Suppose we are to determine the formula for an ionic compound composed of sodium ion and chloride ion. 𝑁𝑎! 𝐶𝑙 " 𝑁𝑎#𝐶𝑙# or 𝑁𝑎𝐶𝑙 the 1 in -1 charge becomes the 1 in +1 charge becomes we do not write the subscript 1 the subscript of Na the subscript of Cl as it is obvious We crisscross the number of the charge to make it the subscript. The name of an ionic compound is cation’s name followed by anion’s name. The name of this compound is sodium chloride with formula 𝑁𝑎𝐶𝑙 17 Formula of Ionic Compounds Suppose we are to determine the formula for an ionic compound composed of calcium ion and bromide ion. 𝐶𝑎$! 𝐵𝑟 " 𝐶𝑎#𝐵𝑟$ or 𝐶𝑎𝐵𝑟$ the 1 in -1 charge becomes the 2 in +2 charge becomes we do not write the subscript 1 the subscript of Ca the subscript of Br as it is obvious The name of the compound is calcium bromide with a formula 𝐶𝑎𝐵𝑟2 18 9 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Formula of Ionic Compounds Suppose we are to determine the formula for an ionic compound composed of barium ion and oxide ion. 𝐵𝑎$! 𝑂$" 𝐵𝑎$𝑂$ or 𝐵𝑎𝑂 the 2 in -2 charge becomes the 2 in +2 charge becomes Reduce the subscripts to the subscript of Ba the subscript of O lowest terms if possible The name of the compound is barium oxide with a formula 𝐵𝑎𝑂 19 Formula of Ionic Compounds Suppose we are to determine the formula for an ionic compound composed of ammonium ion and phosphate ion. 𝑁𝐻%! 𝑃𝑂%&" 𝑁𝐻! " 𝑃𝑂! # or 𝑁𝐻! " 𝑃𝑂! the 3 in -3 charge becomes the 1 in +1 charge becomes Note that the polyatomic ions must be enclosed in a parenthesis if they have a subscript the subscript of (NH4) the subscript of (PO4) greater than 1. You can remove the parenthesis if the subscript is 1. The subscript of the polyatomic ion should be outside the parenthesis. The name of the compound is ammonium phosphate with a formula 𝑁𝐻3 4𝑃𝑂3 20 10 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Ionic Compounds: Exercises I.Name the following: II. Identify the formula: 1. 𝐾2𝑆𝑂3 1. Strontium nitride 2. 𝐵𝑎 𝑂𝐻 2 2. Barium sulfate 3. Calcium hydrogen carbonate 3. 𝑁𝐻3𝐵𝑟 4. Nickel (II) perchlorate 4. 𝐶𝑟2𝑂4 5. Sodium cyanide 5. 𝐶𝑜 𝑁𝑂4 2 21 Formulas of Acids Acids are ionic compounds whose cation is solely hydronium ion 𝐻 1. The number of 𝐻 1 ions in the formula for acid should be equal to the numerical charge of the anion pair. For an acid with anion 𝑆𝑂325, there should be 2 𝐻 1 and the formula is 𝐻2𝑆𝑂3. If it is one oxygen less, it would be called a bisulfate ion 𝐻𝑆𝑂35. 22 11 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Rules in Naming Acids Acids whose anions with suffix –ide are named by changing –ide to –ic followed by the word acid. A prefix hydro- is also needed. Anion Anion Name Acid Formula Acid Name 𝐹% Fluoride ion 𝐻𝐹 Hydrofluoric acid 𝐶𝑙% Chloride ion 𝐻𝐶𝑙 Hydrochloric acid 𝐵𝑟 % Bromide ion 𝐻𝐵𝑟 Hydrobromic acid 𝐶𝑁 % Cyanide ion 𝐻𝐶𝑁 Hydrocyanic acid 23 Rules in Naming Acids Acids whose anions with suffix –ate and -ite are named by changing –ate to –ic and –ite to –ous, followed by the word acid Anion Anion Name Acid Formula Acid Name 𝐶𝑙𝑂$% Perchlorate ion 𝐻𝐶𝑙𝑂$ Perchloric acid 𝐶𝑙𝑂#% Chlorate ion 𝐻𝐶𝑙𝑂# Chloric acid 𝐶𝑙𝑂"% Chlorite ion 𝐻𝐶𝑙𝑂" Chlorous acid 𝐶𝑙𝑂% Hypochlorite ion 𝐻𝐶𝑙𝑂 Hypochlorous acid 24 12 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Formulas of Bases Bases are ionic compounds whose anion is solely hydroxide ion 𝑂𝐻 5. The number of 𝑂𝐻 5 ions in the formula for base should be equal to the numerical charge of the cation pair. For a base with cation 𝐵𝑎21, there should be 2 𝑂𝐻 5 and the formula is 𝐵𝑎 𝑂𝐻 2. 25 Rules in Naming Bases We name cations first and then anion with rules like previously discussed. Just add the ending hydroxide. Cation Cation Name Base Formula Base Name Iron (II) hydroxide 𝐹𝑒 "! Iron (II) / Ferrous 𝐹𝑒 𝑂𝐻 " Ferrous hydroxide Iron (III) hydroxide 𝐹𝑒 #! Iron (III) / Ferric 𝐹𝑒 𝑂𝐻 # Ferric hydroxide 𝐴𝑙#! Aluminum 𝐴𝑙 𝑂𝐻 # Aluminum hydroxide 𝑁𝑎! Sodium 𝑁𝑎𝑂𝐻 Sodium hydroxide 26 13 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Names of Hydrates Hydrates are ionic compounds with specific number of water molecules attached to the molecule. We indicate the number of hydrates by using Greek prefixes then the word hydrate. Hydrate Name 𝐵𝑎𝐶𝑙" 7 2 𝐻"𝑂 Barium chloride dihydrate 𝐿𝑖𝐶𝑙 7 𝐻"𝑂 Lithium chloride monohydrate 𝑀𝑔𝑆𝑂$ 7 7 𝐻"𝑂 Magnesium sulfate heptahydrate Copper (II) sulfate pentahydrate 𝐶𝑢𝑆𝑂$ 7 5 𝐻"𝑂 Cupric sulfate pentahydrate 27 Names of Binary Molecules Binary molecular compounds are covalent molecules with two elements only. Example 𝐶𝑂2 𝑆𝑂2 𝑁𝑂2 Naming is same to that of the ionic compounds. 28 14 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Formula for Binary Molecules The name of the element farther to the left of the periodic table is usually written first. If it contains oxygen, we write the oxygen always as the last. Example 𝐻2𝑂 is written this way since 𝐻 is the leftmost element in PT 𝐶𝑙𝑂35 is written this way, not 𝑂3𝐶𝑙 5, since 𝑂 should always be at the last (the naming rule for this is the rule for anions) 29 Formula for Binary Molecules If both elements are in the same group in the periodic table, write the heaviest element first. Example 𝑆𝑂2 is written this way, not 𝑂2𝑆, since 𝑆 is heavier than 𝑂 and it should follow the previous rule about writing 𝑂 30 15 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Rules in Naming Binary Molecules Now we know the order of element in writing binary molecules, we name the second element with an ending –ide. Also, indicate the number of the second element using Greek prefix mono-, di-, tri-... If the second element’s name begins with vowels (such as oxide), drop the a or o in the prefix. Do not use mono- prefix for the first element. 31 Rules in Naming Binary Molecules Example Molecule Name Note 𝑁𝐹# Nitrogen trifluoride No mono- for nitrogen 𝐶𝑙"𝑂 Dichlorine monoxide Not monooxide. Drop the o 𝑁"𝑂$ Dinitrogen tetroxide Not tetraoxide. Drop the a 𝑃$𝑆&' Tetraphosphorus decasulfide 32 16 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Chemical Equation Writing 33 Chemical Equations Terms A chemical reaction is a process in which a substance Reactants are the substances being used in a is transformed into another substance/s. chemical reaction Products are the substances being produced in a Chemical Reactions are always represented using chemical reaction chemical equations Reaction arrow indicates the direction of the reaction. It could be single-headed arrow → or reactants products an equilibrium arrow ⇌ Chemical formula represent the number and 𝐶4𝐻> 𝑔 + 5 𝑂2 𝑔 → 3 𝐶𝑂2(𝑔) + 4 𝐻2𝑂(𝑔) types of atoms present in a substance chemical formula Subscript indicates the number of a specific subscript atoms in a chemical formula state of matter coefficient or Coefficient or stoichiometric coefficient tells you stoichiometric coefficient the correct proportion of the substance needed in a chemical reaction reaction arrow State of matter represent whether the substance is in solid (𝑠), liquid (𝑙), gas (𝑔), or dissolved in water (𝑎𝑞), known as aqueous 34 17 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Writing Chemical Equations from Words Writing chemical equation from sentences is easy if you recognize some keywords and you know the chemical formula based on its name. Example Calcium hydroxide reacts with hydrochloric acid to produce calcium chloride and water. Calcium hydroxide reacts with hydrochloric acid to produce calcium chloride and water. 𝐶𝑎 𝑂𝐻 " 𝐻𝐶𝑙 𝐶𝑎𝐶𝑙" 𝐻" 𝑂 This tells you that 𝐶𝑎 𝑂𝐻 ! This tells you that 𝐶𝑎𝐶𝑙! Therefore, the formula and 𝐻𝐶𝑙 areisreactants 𝐶𝑎 𝑂𝐻 2 + 𝐻𝐶𝑙 → !𝐶𝑎𝐶𝑙2 + 𝐻2 𝑂 or 𝐶𝑎 𝑂𝐻 and 𝐻 𝑂 are products 2 + 2 𝐻𝐶𝑙 → 𝐶𝑎𝐶𝑙2 + 2 𝐻2𝑂 when balanced. 35 Writing Chemical Equations from Words Writing chemical equation from sentences is easy if you recognize some keywords and you know the chemical formula based on its name. Example Methane burns with oxygen to form carbon dioxide and water. 𝐶𝐻$ 𝑂" 𝐶𝑂" 𝐻" 𝑂 This tells you that 𝐶𝐻" This tells you that 𝐶𝑂! and 𝑂! are reactants and 𝐻!𝑂 are products Therefore, the formula is 𝐶𝐻3 + 𝑂2 → 𝐶𝑂2 + 𝐻2𝑂 or 𝐶𝐻3 + 2 𝑂2 → 𝐶𝑂2 + 2 𝐻2𝑂 when balanced. 36 18 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 Writing Chemical Equations from Words Tips These are some keywords used in sentences describing chemical equations. It would be handy if you are able to recognize these: Keywords for reactants Keywords for products reacts with to produce / produces combusted with to yield / yields combined with to form / forms The reaction between … decomposes to produce … 37 Exercises 1. Glucose is combusted with oxygen to produce carbon dioxide and water. 2. Methanol is combusted with oxygen to form carbon dioxide and water. 3. Lithium reacts with water to form lithium hydroxide and hydrogen gas. 4. The reaction of ammonia and carbon dioxide produces urea 𝑁𝐻2 2𝐶𝑂 and water 5. Methanol is formed from carbon monoxide and hydrogen gas. 38 19 FEU Biochemistry Property. All forms of replicatin are prohibited. Seek approval from Ms. Jessa Natividad and Ms. Erika Viloria 8/13/24 END Thank you for listening! 39 20