Chapter 2A: Antacids Why do we need antacids? Your body needs hydrochloric acid to digest food Too much causes heartburn, ulcers and can damage your esophagus Antacids versus Acid Inhibitors There are two types of medicines you can use Antacids Acid Inhibitors Neutralizes the acid currently in your system Controls the amount of acid your body produces Work quickly but your body will make more acid again Long-term solution, but needs to build up in your system to be most effective Alka-Seltzer ®, Rolaids ®, Tums ®, Malox ®, Mylanta ® Tagamat ®, Zantac ®, Pepcid AC ® Is it fair when a commercial compares the fast action of an antacid to an acid inhibitor that takes up to 7 days to build up? Antacids This chapter will introduce the chemistry needed to understand how antacids work Section 2.1: Types of Matter Section 2.2a: Identifying Ions Section 2.2b: Naming Ionic Compounds Section 2.2c: Naming Covalent Compounds Section 2.3: Writing Formulas for Ionic & Covalent compounds Section 2.1—Types of Matter Matter is…. Anything that has mass and takes up space (volume) Anything made from atoms Examples: elements, molecules, cells, people, air, water, paper Non Examples: dreams, energy (light, heat), emotions Pure Substances versus Mixtures Matter is classified as either a pure substance or a mixture Pure Substances Contain only 1 type of particle Elements or Compounds Mixtures Contain 2 or more pure substances Homogeneous or Heterogeneous Pure Substances Elements Simplest kind of matter Made of only 1 kind of atom Cu, Ag, Fe, Br2 Compound 2 or more elements chemically bonded together to form molecules. Each is the same fixed ratio of elements. H2O, NaCl, CO2 Elements Single Atom Element Cannot be separated by chemical or physical processes Pure substance Every atom is the same Elements can be found on the periodic table! Elements http://www.youtube.com/watch?v=7FesjAdIWBk Compounds Single Molecule Made of more than one type of atom bonded together Compound Pure substance Every molecule is the same Can only be separated by chemical reactions Mixtures More than 1 different type of matter Mixture Not a pure substance Physical combination of more than 1 type of pure substance Can be separated physically by Distillation Filtration Chromatography Mixtures Mixtures can be classified as homogeneous or heterogeneous Homogeneous (aka “solution”) It looks the same throughout; substances evenly dispersed Ex. salt water, alloys, clean air Heterogeneous Different substances can be seen (chunks, bubbles, floaties, layers) Ex. salad dressing, fog, chocolate chip cookies, soil Mixture possibilities Mixtures can be any combination of solids, liquids and gases: Solid-solid: Medicine tablet Solid-gas: Pop Rocks candy Solid-liquid: Ice water Liquid-liquid: lemon water Gas-Liquid: Carbonated water Gas-Gas: Air Homogeneous Mixtures Kool-Aid: sugar in water Brass: copper in zinc Air: oxygen gas in nitrogen gas Milk: fat, proteins, sugar in water Heterogeneous Mixtures Oil in water Italian Salad Dressing Chicken Noodle Soup Fruit Salad Classification of Matter True Solutions, Colloids & Suspensions Homogeneous Heterogeneous True Solution Colloid particles don’t settle out and are too small to scatter light Ex: salt water, air, brass INTERMEDIATE SMALL particles don’t settle out but are large enough to scatter light: Ex: fog, foam, jello, paint Dissolved Particle Size Increases Heterogeneous Suspension LARGE particles that settle out over time Ex: oral medicines, italian dressing, paint True Solutions Suspensions vinegar and oil salad dressing Particles Scattering Light If the dissolved particles are large enough to scatter light, we say it exhibits the “Tyndall Effect” Solution Light passes through unchanged Colloids exhibit the Tyndall Effect Light is scattered by larger solute particles Connect these concepts with Antacids What type of matter do you think antacids are? Pure substance (Element or compound) Mixture (homogeneous or heterogeneous) Connect these concepts with Antacids Antacids are mixtures. They contain active & inactive ingredients What purposes could the inactive ingredients serve? Connect these concepts with Antacids Inactive ingredients might Add volume to make the pill able to be handled Add color and flavor Allow the tablet to be compressed and formed Let’s Practice: Not in Notes Example: Determine if each is element, compound, homogeneous or heterogeneous mixtures Tin can (Sn) Copper pipe (Cu) Concrete Carbon tetrachloride(CCl4) Sports drink Let’s Practice Example: Determine if each is element, compound, homogeneous or heterogeneous mixtures Tin Element Copper pipe Element Concrete Heterogeneous mix Carbon tetrachloride Compound Sports drink Homogenous mix You Try! In Notes Example: Determine if each is element, compound, homogeneous or heterogeneous mixtures Aluminum foil (Al) Water (H2O) soda soil Carbon dioxide(CO2) Tap water You Try! Example: Determine if each is element, compound, homogeneous or heterogeneous mixtures Aluminum foil (Al) Element Water (H2O) Compound Flat soda Homogeneous mix soil Heterogeneous mix Carbon dioxide(CO2) compound Tap water Homogeneous mix The Science of Macaroni Salad http://www.freetech4teachers.com/2013/08/t he-science-of-macaronisalad.html#.UkySCODvSDo Section 2.2a—Naming Chemicals We need to be able to name the chemicals in the antacids! Section 2.2a—Identifying Ions We need to be able to name the chemicals in the antacids! The Language of Chemistry Chemistry has a language all of its own Chemistry English Element Symbols Letters Chemical Formulas Words Chemical Equations Sentences Each element symbol starts with a capital letter ELEMENTS: made of atoms An atom consists of subatomic particles There are 3 subatomic particles: protons, electrons and neutrons Neutral atoms have the same number of protons and eletrons IONS An atom or group of atoms with a charge. The number of protons does not equal the number of electrons. WHY? Atoms can gain or lose electrons to acquire stability like a noble gas element. The Periodic Table of Elements Metals form cations NonMetals form anions H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Lr Rf Db Sg Bh Hs Mt Uun Uuu Uub Uut Metals Metalloids Nonmetals Monatomic Ions (formed from a single atom) Cations Positive charge Metal atoms that lose electrons Group A (Representative metals/Type I ) The group # for metals in columns 1A, 2A, & 3A is equal to the charge of the cation Naming them: Take the element name and add the word ion Monatomic Ions of Group A /Type I Metals Group A Group A Group B Group B (Transition/Type II Metals): have more than one charge You should be familiar with the following transition metals with more than one charge. Naming them: Take Fe+2 Fe+3 the element name Sn+2 Sn+4 and place in +2 +4 Pb Pb parentheses the Co+2 Co+3 charge number as a Cr+2 Cr+3 roman numeral and Mn+2 Mn+3 add the word ion Cu+1 Cu+2 Monatomic Ions of Transition/Type II Metals + Monatomic Ions (formed from a single atom) Cu+2, F-1 Anions Negative charge Nonmetals that gain electrons Group A (Representative nonmetals) Subtract the group # in columns 4A, 5A, 6A, and 7A from 8 to get the charge. Naming them: Drop the ending of the element and add –ide and then ion You Try! Try These: Write the formula for each ion and name it. Calcium Chromium Chlorine Sulfur You Try! Try These: Write the formula for each ion and name it. Calcium Ca+2 calcium ion Chromium Cr+2 chromium(II) ion Cr+3 chromium (III) ion Chlorine Cl-1 chloride ion Sulfur S-2 sulfide ion Self Check Try These: Write the formula for each ion and name it. +3 Aluminum Ion Al Aluminum +2 Zinc ion Zn Zinc Fe+2 Iron (II) ion or Iron Fe+3 Iron (III) ion Phosphorus P-3 Phosphide ion Section 2.2b—Naming Ionic Compounds We need to be able to name the chemicals in the antacids! Binary Ionic Compounds Binary Ionic Compound- compound containing 2 elements—one metal and one non-metal The atoms are held together by Ionic Bondsbond formed by attraction between + ions and – ions Metal Nonmetal + Cation Anion Ionic Compound Metals & Non-Metals Ionic Bonds are between metals & non-metals H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Lr Rf Db Sg Bh Hs Mt Uun Uuu Uub Uut Metals Metalloids Nonmetals How to Identify & Name a Binary Ionic Compound Look for: 2 elements (“binary”) A type I metal & a non-metal (“ionic”) To name these compounds: Write the name of the type 1 metal (the cation) Write the name of the non-metal (the anion) with the suffix “-ide” The subscripts in the formula do not matter when naming this type Example #1 NaCl “Sodium” Cation NaCl Anion “Chlorine” becomes “Chloride” Sodium Chloride Example #2 CaBr2 “Calcium” Cation CaBr2 Anion “Bromine” becomes “Bromide” Calcium Bromide Example #3 K2O “Potassium” Cation K2O Anion “Oxygen” becomes “Oxide” Potassium Oxide Self Check Li2O Example: Write the name for the following compounds Sr3P2 MgS BaI2 Answers Example: Write the name for the following compounds Li2O Lithium oxide Sr3P2 Strontium phosphide MgS Magnesium sulfide BaI2 Barium iodide Ternary Ionic Compounds Ternary Ionic Compound- a compound containing at least one polyatomic ion Polyatomic Ion- an ion that has more than one atom that together have a single charge + Cation + Polyatomic Cation - Polyatomic Anion Anion Ternary Ionic Compound Common Polyatomic Ions You don’t need to memorize them. Look at your reference sheet. COMMON POLYATOMIC IONS Acetate, CH3COO-1 or C2H3O2-1 Ammonium NH4+1 Bromate, BrO3-1 Bromite, BrO2-1 Carbonate, CO3-2 Carbonite, CO2-2 Chlorate, ClO3-1 Chlorite, ClO2-1 Chromate, CrO4-2 Cyanide, CN-1 Dichromate, Cr2O7-2 Dihydrogen phosphate, H2PO4-1 Hydrogen carbonate or bicarbonate, HCO3-1 Hydrogen phosphate or biphosphate, HPO4-2 Hydrogen sulfate or bisulfate, HSO4-1 Hydroxide, OH-1 Hypochlorite, ClO-1 Iodate, IO3-1 Iodite, IO2-1 Nitrate, NO3-1 Nitrite, NO2-1 Oxalate, C2O4-2 Perchlorate, ClO4-1 Permanganate, MnO4-1 Peroxide, O2-2 Phosphate, PO4-3 Phosphite, PO3-3 Silicate, SiO3-1 Sulfate, SO4-2 Sulfite, SO3-2 Identifying Polyatomic Ions: Hints The only cation (front-half) polyatomic ion is “NH4+” All other polyatomic ions are anions (backhalf) The subscripts within the polyatomic ion are important (it must match exactly with the one on your ion list) If there are parentheses, the polyatomic ion is inside (ignore the number outside) Practice Identifying Polyatomic Ions Example: Underline& name the polyatomic ion in each compound NaNO3 NH4Cl Ca(OH)2 (NH4)3PO4 K2CO3 Practice Identifying Polyatomic Ions Example: Identify and name the polyatomic ion in each compound NaNO3 Nitrate NH4Cl Ammonium Ca(OH)2 Hydroxide (NH4)3PO4 Ammonium & phosphate K2CO3 Carbonate How to Identify & Name Ternary Ionic Compounds Look for: More than 2 capital letters next to one another (not starting with H) Contain at least 1 metal & 1 non-metal To name these compounds: Write the name of the cation (either the metal element name or “Ammonium” for “NH4+”) If the anion is a polyatomic ion, write the given polyatomic ion’s name If the anion is a single non-metal element, write its name with the suffix “-ide” Example # 4 Ca(NO3)2 “Calcium” Cation Ca(NO3)2 Polyatomic Anion “Nitrate” Calcium Nitrate Example #5 Na3PO4 “Sodium” Cation Na3PO4 Polyatomic Anion “phosphate” Sodium phosphate Example # 6 K2CO3 “potassium” Cation K2CO3 Polyatomic Anion “carbonate” Potassium carbonate Self Check Ca(C2H3O2)2 Example: Write the name for the following compounds Li2SO3 Ba(OH)2 (NH4)2S Answers Ca(C2H3O2)2 Calcium acetate Example: Write the name for the following compounds Li2SO3 Lithium sulfite Ba(OH)2 Barium hydroxide (NH4)2S Ammonium Sulfide Worksheet 1 (1-10 Answers) 1. Sodium sulfide 6. Silver chloride 2. Aluminum oxide 7. Boron nitride 3. Sodium chloride 8. Barium fluoride 4. Rubidium iodide 9. Strontium nitride 5. Zinc bromide 10. Magnesium chloride Worksheet 2 (1-10 Answers) 1. copper(I) fluoride 6.chromium (VI) oxide 2. copper (II) fluoride 7. gold(I) bromide 3. chromium (III) oxide 8. nickel(II) oxide 4. lead (II) iodide 10. tin(IV) oxide 5. lead (IV) chloride 9. vanadium(III) iodide Worksheet 3 (1-10 Answers) 1. vanadium(V) chlorate 2. rhenium(VI) sulfate 3. osmium(III) iodate 4. iridium(IV) phosphate 5. palladium(IV) sulfite Gold(I) nitrate 7. iron(III) phosphite 8. nickel(II) bromate 9. lead(IV) sulfide 10. Manganese (VII) dichromate Worksheet 4 (1-10 Answers) 1. ammonium chloride 6. ammonium nitrate 2. hydrogen chlorite 7. strontium phosphate 3. calcium bromate 8. zinc chlorate 4. beryllium sulfate 9. silver iodate 5. ammonium nitride 10. potassium dichromate Transition Metals Revisisted Transition Metal- group “B” or Type II metal that has the possibility of having more than one cation charge; Common multivalent metals and their charges Cobalt Copper Iron Manganese Mercury Co+2 Cu+1 Fe+2 Mn+2 Hg2+2 Co+3 Cu+2 Fe+3 Mn+3 Hg+2 IMPORTANT: Although group B metals, SILVER (+1), CADMIUM (+2), and ZINC (+2) only have 1 charge Although the elements of TIN and LEAD are group A elements, they do have more than one charge Sn(+2 and +4) and Pb(+2 and +4) How to Identify & Name Ionic Compounds with Transition Metals Look for: One of the transition metals, excluding Ag, Cd, and Zn To name these compounds: Write the name of the Type II metal element (cation) Write the name of the anion (element name with “-ide” or polyatomic ion name) Determine the charge of the transition metal 1. Total negative charge = total positive charge for all neutral compounds 2. Divide total positive charge by the number of metal atoms 3. Write the charge in roman numerals in parentheses after the Type II metal’s name Example # 7 CuCl “Copper” Cation CuCl Anion “Chlorine” becomes “Chloride” Copper Chloride “Copper” Cation Chloride has a –1 charge CuCl Anion “Chlorine” becomes “Chloride” -1 charge * 1 ion = -1 A –1 charge needs a +1 charge Therefore, copper must be +1, (I) Copper (I) Chloride Example # 8 Fe2(CO3)3 “Iron” Cation Fe2(CO3)3 Polyatomic Anion “Carbonate” Iron carbonate “Iron” Cation Carbonate has a –2 charge Fe2(CO3)3 Polyatomic Anion “Carbonate” -2 charge * 3 ions = -6 A –6 charge needs a +6 charge and there are 2 iron ions Therefore, iron must be +3 (III) Iron (III) carbonate Example # 9 ZnBr2 “Zinc” Cation ZnBr2 monatomic Anion “bromide” Zinc bromide “Zinc” Cation bromide has a –1 charge ZnBr2 Polyatomic Anion “bromide” -1 charge * 2 ions = -2 A –2 charge needs a +2 charge and there is 1 zinc ion Therefore, zinc must be +2 (not needed) it only has one charge Zinc bromide Self Check PbCl2 Example: Write the name for the following compounds PbCl4 MnO Mn2O3 Answers Example: Write the name for the following compounds PbCl2 Lead (II) chloride PbCl4 Lead (IV) chloride MnO Manganese (II) oxide Mn2O3 Manganese (III) oxide Section 2.2b—Naming Covalent Compounds We need to be able to name the chemicals in the antacids! Binary Covalent (Molecular) Compounds Binary Molecular Compounds are made from two non-metals that are covalently bonded Covalent bond a bond formed from atoms that share electrons Non metal Non metal Covalent compound Identifying & Naming Binary Molecular These compounds have: 2 elements (“binary”) Both non-metals (“covalent”) To name these compounds: Write the name of the first element with the prefix indicating the number of atoms (except don’t use “mono-” if only 1 atom) Write the name of the second element with the prefix indicating the number of atoms (including “mono-”) and the suffix “ide” Covalent Prefixes PREFIXES USED IN MOLECULAR COMPOUNDS 1. mono 2. di3. tri4. tetra5. penta6. hexa7. hepta8. octa9. nona10.deca- Example #10 P2O5 2 = “di-” Phosphorus P2O5 Oxygen 5 = “penta-” “oxide” Diphosphorus pentaoxide Example #11 SiF4 Don’t use “mono-” on first element Silicon SiF4 Fluorine 4 = “tetra-” “fluoride” Silicon tetrafluoride Self Check SO2 Example: Write the name for the following compounds N2Cl4 P4O10 CO Answers Example: Write the name for the following compounds SO2 sulfur dioxide N2Cl4 Dinitrogen tetrachloride P4O10 Tetraphosphorus decaoxide CO Carbon monoxide Mixed Practice: Determine the type of compound, Ionic (m/nm) or Covalent (nm/nm) & then follow rules Na2O Example: Write the name for the following compounds K3PO4 Cu(OH)2 N2S MgCl2 Answers Example: Write the name for the following compounds Na2O Sodium oxide K3PO4 Potassium phosphate Cu(OH)2 Copper (II) hydroxide N2S Dinitrogen monosulfide MgCl2 Magnesium chloride Section 2.3—Writing Chemical Formulas For Ionic & Covalent Compounds We need to be able to read the formulas for chemicals in the antacids! Reminders from Section 2.2 Your Reference sheet has a list of: Common polyatomic ions Use your periodic table is used to determine the charges of common elements when they form ions You must memorize the 10 prefixes for covalent compounds Binary Ionic Compounds containing two elements—one metal and one non-metal formed by attraction between + and ions + Cation Anion Ionic Compound How to Write Formulas for Binary Ionic Compounds These compounds: End in “-ide” (except “hydroxide and cyanide”) Do NOT contain covalent prefixes To write these formulas: Write the symbol & charge of the first element (the metal, cation) Write the symbol & charge of the second element (the non-metal, anion) Add more of the cations and/or anions to have a neutral compound Use subscripts to show how many of each type of ion is there. Example #1 Sodium chloride Na+1 Cation Sodium chloride Anion Cl-1 NaCl Example #1 Na+1 Cation Na+1Cl-1 Sodium chloride Anion Cl-1 NaCl +1 + -1 = 0 The compound is neutral…no subscripts are needed. Example #2 Calcium bromide Example #2 Ca+2 Cation Calcium bromide Anion Br-1 Example #2 Ca+2 Cation Ca+2 Br-1 Calcium bromide Anion Br-1 CaBr2 +2 + -1 = +1 Ca+2 Br-1 Br-1 +2 + -1 + -1 = 0 The subscript “2” is used to show that 2 anions are needed. A Simple Method to Writing Binary Ionic Formulas The Criss - Cross Method: Write the symbol & charge of the first element (the metal, cation) Write the symbol & charge of the second element (the non-metal, anion) Cross ONLY the charge numbers down diagonally to make subscripts IF they are not equal to each other Simplify subscripts if you can Ca +2 Br-1 Ca1Br2 1 2 CaBr2 Self Check Cesium chloride Example: Write the following chemical formulas Potassium oxide Calcium sulfide Lithium nitride Answers Example: Write the following chemical formulas Cesium chloride CsCl Potassium oxide K2O Calcium sulfide CaS Lithium nitride Li3N Ternary Ionic Compounds compound containing at least one polyatomic ion Either in the front, the back or in both places + Cation Polyatomic Anion Polyatomic Ionic Compound How to Identify & Name Ternary Ionic Compounds These compounds: Do not end with “-ide” (except hydroxide & cyanide) Do not use covalent prefixes To write these formulas: Write the symbol & charge of the cation & anion Add additional cations or anions to have a neutral compound Use subscripts to show the number of ions When using subscripts with a polyatomic ion, you must put the polyatomic ion in a parenthesis with the subscript on the outside Example #3 Sodium carbonate Na+1 Cation Sodium carbonate Polyatomic Anion CO3-2 Na+1 Cation Na1+ CO32- Sodium carbonate Polyatomic Anion CO3-2 Na2CO3 +1 + -2 = -1 Na+ Na+ CO32+1 + 1 + -2 = 0 The subscript “2” is used to show that 2 cations are needed. Example #4 Magnesium nitrate Mg+2 Cation Magnesium nitrate Polyatomic Anion NO3-1 Mg+2 Mg+2NO31- Cation +2 + -1 = 1 Magnesium nitrate Mg+2 NO3- NO3- Polyatomic Anion NO3-1 Mg(NO3)2 +2 + -1 + -1 = 0 The subscript “2” is used to show that 2 anions are needed. Use parenthesis when adding subscripts to polyatomic ions Self Check Sodium nitrate Example: Write the following chemical formulas Calcium chlorate Potassium sulfite Calcium hydroxide Answers Example: Write the following chemical formulas Sodium nitrate NaNO3 Calcium chlorate Ca(ClO3)2 Potassium sulfite K2SO3 Calcium hydroxide Ca(OH)2 Transition Metals metal that has more than one possibility for cationic charge How to Identify & Name Ionic Compounds with Transition Metals These compounds: Will have roman numerals To write these formulas: Same as binary ionic or polyatomic ionic. The roman numerals tell the charge of the metal (cation) Example #5 Iron (III) oxide Fe+3 Cation Iron (III) oxide Anion O-2 Fe+3 Fe+3 O2- Cation Iron (III) oxide +3 + -2 = -1 Fe+3 Fe+3 O2- O2- Anion +3 + 3 + -2 + -2 + -2 = 0 O-2 Fe2O3 The subscript “2” and “3” are used to show the numbers of atoms needed. Example #6 Copper (II) nitrate Cu+2 Cation Copper (II) nitrate Polyatomic Anion NO3-1 Cu+2 Cu+2 NO31- Cation Copper (II) nitrate +2 + -1 = 1 Cu+2 NO3- NO3- Polyatomic Anion +2 + -1 + -1 = 0 NO3-1 Cu(NO3)2 Use parenthesis when adding subscripts to a polyatomic ion Self Check Iron (II) nitrate Example: Write the following chemical formulas Copper (I) chloride Lead (IV) hydroxide Tin (II) oxide Answers Example: Write the following chemical formulas Iron (II) nitrate Fe(NO3)2 Copper (I) chloride CuCl Lead (IV) hydroxide Pb(OH)4 Tin (II) oxide SnO Binary Covalent Compounds compound made from two nonmetals between atoms that share electrons Non metal Non metal Covalent compound How to Identify & Name Binary Covalent Compounds These compounds: Use covalent prefixes To write these formulas: Write the symbols of the first and second element Use the covalent prefixes (assume the first element is “1” if there’s no prefix) as the subscripts to show number of atoms. Atoms do not form charges when bonding covalently…you DO NOT need to worry about charges with this type! NOR CRISS CROSS METHOD! Example #7 Dinitrogen Tetraoxide “Di-” = 2 N Dinitrogen Tetraoxide O “Tetra-” = 4 N2O4 Example #8 Silicon dioxide “Mono-” is not written for the first element Si Silicon dioxide O “Di-” = 2 SiO2 CAUTION!!! “di” and “bi” do not mean the same thing! di- bi- Stands for “2” in covalent compounds Means there’s a hydrogen in the polyatomic anion Carbon dioxide = CO2 Sodium biphosphate = Na2HPO4 Self Check Carbon monoxide Example: Write the following chemical formulas Sulfur tetraiodide Trichlorine pentasulfide Answers Example: Write the following chemical formulas Carbon monoxide CO Sulfur tetraiodide SI4 Trichlorine pentasulfide Cl3S5 Self Check: Mixed Practice Magnesium hydroxide Example: Write the following chemical formulas Copper (II) nitrate Iron (III) oxide Nitrogen dioxide Sodium bicarbonate Answers Example: Write the following chemical formulas Magnesium hydroxide Mg(OH)2 Copper (II) nitrate Cu(NO3)2 Iron (III) oxide Fe2O3 Nitrogen dioxide NO2 Sodium bicarbonate NaHCO3