University of Santo Tomas Chemistry Notes (PDF)

TOPIC 2A: ATOMS, MOLECULES, IONS TOPIC 2B: CHEMICAL FORMULAS SUBTOPICS (Please refer to your LAICO): ✔Dalton’s Atomic Theory ✔Basic Laws of Matter ✔Atomic Structure ✔Subatomic Particles ✔Molecules, Ions and Isotopes *Chemical Formulas – wr...

TOPIC 2A: ATOMS, MOLECULES, IONS TOPIC 2B: CHEMICAL FORMULAS SUBTOPICS (Please refer to your LAICO): ✔Dalton’s Atomic Theory ✔Basic Laws of Matter ✔Atomic Structure ✔Subatomic Particles ✔Molecules, Ions and Isotopes *Chemical Formulas – writing and naming © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.  CHEMICAL FORMULA NAMING & WRITING CHAPTER 2 – Chemistry: Atoms, Molecules, Ions Katherine Kyra D. Alonday-Lactaoen, RPh, LPT, MSc, CIP STEM Faculty member University of Santo Tomas Senior High School Department © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education. Modern Periodic Table of Elements NON- METALS METALS What is the importance and relevance of knowing whether an atom is a metal or a non-metal?  Two Types of Chemical Bonds: 1. IONIC BOND NON- METALS METALS 2. COVALENT NON- BOND NON- METALS METALS Compounds – pure substances with 2 or more atoms that are chemically bound.  “Ionic compounds” IONIC BOND NON- METALS TRANSFER METALS IONIC BOND (transfer) Sodium and Chlorine Na and Cl Na+ and Cl- Metals become CATIONS and non-metals become ANIONS. https://courses.lumenlearning.com/ivytech-bio1-1/chapter/reading-ionic-bonds/ COVALENT BOND (share) “Covalent compounds” 2 Chlorine atoms or “Molecules” Cl- and Cl- COVALENT BOND Cl2 NON- SHARE NON- METALS METALS Electron pair Covalent bond First Cl atom Second Cl atom Covalent compounds, since they share, both atoms achieve “stability”. http://obd2.autoscout24.com/portfolio/blitzer-de/gallery/alle/dot-diagram-fluorine.html PERIODS or SERIES: Arranged horizontally across the periodic table (rows 1-7). These elements have the same number of valence shells or energy level. ENERGY https://logos-download.com/1227-royal-dutch-shell-logo-download.html https://en.wikipedia.org/wiki/Periodic_table FAMILY or GROUP: Arranged vertically down the periodic table. These elements have the same number of valence electrons per group. “VALENCE ELECTRON” means the outermost electron/(s) “OCTET” RULE Dictates the stability of each atom when it achieves 8 valence electrons. “DUET” RULE Stability of Hydrogen and Helium when they achieve 2 valence electrons. https://en.wikipedia.org/wiki/Periodic_table  REPRESENTATIVE (Group TYPES OF GROUPS: A) ELEMENTS Group A – REPRESENTATIVE ELEMENTS Group number is equal to the Group B – TRANSITION ELEMENTS number of valence e-. The common charge of each atom is known. Examples: Sodium (Group 1A) Na has 1 ve- Na+ ion TRANSITION (Group B) ELEMENTS The number of valence electrons have no trend. The common charges of each atom vary. Examples: Gold Au+ lower Au3+ higher https://en.wikipedia.org/wiki/Periodic_table GROUP A: REPRESENTATIVE (Group A) ELEMENTS REPRESENTATIVE ELEMENTS Group number is equal to the number of valence e-. The common charge of each atom is known. Examples: Magnesium (Group 2A) Mg has 2 ve- Mg2+ ion https://www.pinterest.ph/pin/274227064783294939/ GROUP A: Valence e- and Common charge IA IIA IIIA IVA IVA VA VIA VIIA EXAMPLES: Calcium (Grp 2A) 1ve- 2ve- 3ve- 4ve- 4ve- 5ve- 6ve- 7ve- 2ve- Ca2+ +1 +2 +3 +4 -4 -3 -2 -1 Aluminum (Grp 3A) H Be B C C N O F 3ve- Al3+ Li Mg Al Si Si P S Cl Oxygen (Grp 6A) Na Ca Ga Ge Ge As Se Br 6ve- O2- K Sr In Sn Sn Sb Te I Phosphorus (Grp 5A) Rb Ba Tl Pb Pb Bi Po 5ve- P3- GROUP B: TRANSITION (Group B) ELEMENTS TRANSITION ELEMENTS The number of valence electrons have no trend. The common charges of each atom vary. Examples: Gold Au+ lower oxidation number Au3+ higher oxidation number https://www.pinterest.ph/pin/274227064783294939/  Define and differentiate the ff.: Atom , Compound , Molecule , Ion  ATOMS NEUTRAL OR UNCHARGED PARTICLES chemically combine to form lose or gain e- to form COMPOUNDS IONS aggregate of at least 2 atoms chemically an atom or a group of atoms that bound in a definite arrangement. has/have a net charge. ZERO NET CHARGE CHARGED PARTICLES Ex: Na+ Ca2+ Cu2+ Ex: Cl-, O2- N3- DIATOMIC POLYATOMIC ANION CATION 2 counts of atoms More than 2 counts of atoms Homonuclear Ex: CaCO3, KMnO4 H2SO3 and Fe2O3 Ex: O2, N2 and Cl2 METALS NON- Heteronuclear *except H METALS Ex: CO2, HCl and N2O  IONS MONOATOMIC POLYATOMIC Has only 1 atom that is Has 2 or more atoms charged raised in a net charge Na+, Ca2+, Cu2+, Cl-, O2- and N3 CH3COO-, CO32-, PO43-and SO32- CATION ANION CATION ANION Rare in Common in METALS NON- polyatomic polyatomic *except H METALS ions ions Modern Periodic Table of Elements NON- METALS METALS  Why do you think it is important to note the type of atom, compound, or ion that you are trying to chemically write or name? RULES IN CHEMICAL FORMULA NAMING AND WRITING (ION)  MONOATOMIC Ions – Group A Elements ‘Name of element’ ion ‘Root name–ide’ EXAMPLES: E.g. Sodium ion E.g. Fluoride *GROUP A Cations: Ca2+ +1 +2 +3 +4 -4 -3 -2 -1 Calcium ion Li Mg Al C C N O F Al3+ Aluminum ion Na Ca P S Cl *GROUP A Anions: K Sr O2- Rb Ba Se Br Oxide Cs Cations Anions I P3- Phosphide Element Lower oxid # Higher oxid # MONOATOMIC Ions Cu +1 +2 – Group B Elements Hg +1 +2 1. CLASSICAL METHOD Co +2 +3 Latin name and suffixes of Ni +2 +3 either “-ous” or “-ic” Fe +2 +3 Pb +2 +4 Example: Fe Sn +2 +4 a. Lower oxid. # -’ous’ Au +1 +3 E.g. Fe2+ Ferrous As +3 +5 b. Higher oxid. # - ‘ic’ Sb +3 +5 E.g. Fe3+ Ferric Element Lower oxid # Higher Oxid # MONOATOMIC Ions Cu +1 +2 – Group B Elements Hg +1 +2 2. STOCK METHOD Co +2 +3 Uses English name and a Ni +2 +3 Roman numeral Fe +2 +3 Pb +2 +4 Example: Fe Sn +2 +4 Fe2+ Iron (II) Au +1 +3 Fe3+ Iron (III) As +3 +5 Sb +3 +5  POLYATOMIC Ions – List of Common Ions POLYATOMIC CATION NAME POLYATOMIC ANION NAME +1 -1 NH4+ ammonium OH- hydroxide H3O+ hydronium NO2- nitrite NO3- nitrate HCO3- bicarbonate CrO2- chromite CH3COO- acetate (Halogen)O2 ex: ClO2- hal-ite ex: chlorite (Halogen)O3 ex: ClO3- hal-ate ex: chlorate  POLYATOMIC Ions – List of Common Ions POLYATOMIC ANION NAME POLYATOMIC ANION NAME -2 -3 SO32- sulfite BO33- borate SO42- sulfate PO33- phosphite MnO42- manganate PO43- phosphate CO32- carbonate AsO33- arsenite CrO42- chromate AsO43- arsenate C2O42- oxalate POLYATOMIC Ions – Halogens Suffixes with “–ite” means lower F Fluorine FO2- fluorite F- Fluoride ClO2- chlorite FO- Hypofluorite Suffixes with “–ate” means higher FO2- Fluorite FO3- fluorate ClO3- chlorate FO3- Fluorate FO4- Perfluorate Chemical Formula used to express the composition of molecules and ionic compounds in terms of chemical symbols. Types of Chemical Formula 1. MOLECULAR FORMULA – gives the composition of the molecule, in terms of the actual number of atoms present. Example: C6H12O6 2. EMPIRICAL FORMULA – gives the composition of the molecule, in terms of the smallest ratio of the number of atoms present Example: CH2O  Definition of Terms BINARY - made up of 2 elements TERNARY - made up of 3 elements IONIC COMPOUND - made up of Metal + Non metal MOLECULAR COMPOUND - made up of two Non metals ACID - yield hydrogen (H+) ions in aqueous solutions BASE - yield hydroxide (OH-) ions in aqueous solutions Examples: NaCl = Binary ionic compound (2 elements, metal & non metal) HNO3 = Ternary acid (composed of 3 elements and has H+) RULES IN CHEMICAL FORMULA NAMING AND WRITING (COMPOUND)  BINARY IONIC COMPOUNDS (GROUP A) 1. Write the elements (Left Metal, Right Non-metal). Ex: Aluminum + Oxygen 2. Write the charge over the element. Al O 3. Criss-cross the charges and drop. 4. Simplify if necessary. Al3+ O2- +1 +2 +3 +4 -4 -3 -2 -1 Li Mg Al C C N O F Al2- O3+ Na Ca P S Cl K Sr Se Br Al2 O3 Rb Ba Cs I Al2O3  BINARY IONIC COMPOUNDS (GROUP B) 1. Write the elements (Left Metal, Right Non-metal). Ex: Copper + Oxygen 2. Write the charge over the element. 3. Criss-cross the charges and drop. a. LOWER OXID. # Cu O 4. Simplify if necessary. Cu+ O2- Note: Group B has multiple valences. Do both. Cu2- O+ Group B Lower oxid. # Higher oxid. # Cu2 O element Cu2O Cu +1 +2 b. HIGHER OXID. # Cu O Hg +1 +2 Cu2+ O2- Co +2 +3 Cu2- O2+ Ni +2 +3 Cu2 O2 Cu2O2 Fe +2 +3 CuO Exercise 1: Element Lower oxid. # Higher oxid. # Write the empirical chemical formula using initially Cu +1 +2 their common charge/s. If the element comes from Hg +1 +2 Group B, write the answers for both lower and higher oxidation numbers. Co +2 +3 1. Iron and Sulfur Ni +2 +3 Fe +2 +3 2. Hydronium and Bromine Pb +2 +4 3. Calcium and Phosphorus Sn +2 +4 4. Barium and Iodine Au +1 +3 5. Potassium and Acetate As +3 +5 6. Gold and Nitrogen Sb +3 +5 BINARY IONIC COMPOUNDS (GROUP A) Name of the cation + name of the anion”-ide” ROOT NAMES NON-METALS NaI sodium iodide H - hydr MgCl2 magnesium chloride C - carb K2O potassium oxide N - nitr P - phosph O - ox S - sulf BINARY IONIC COMPOUNDS (GROUP B) Se - selen F - fluor Cl - chlor Write the charge in Roman numeral after the the name of the Br - brom cation + name of the anion Cu2O copper (I) oxide CuO copper (II) oxide FeS iron (II) sulfide The basis for naming compounds is their “form” or “charge” BEFORE criss cross!  Given Chemical Chemical Exercise 2: a. Formula Name 1. Iron and Name the chemical formulas from your answers in Sulfur the first Exercise. If you had two answers in one b. item, kindly name both. You may use either the Classical or the Stock Method in naming them. 2. Hydronium and Bromine 1. Iron and Sulfur 3. Calcium and 2. Hydronium and Bromine Phosphorus 3. Calcium and Phosphorus 4. Barium and Iodine 4. Barium and Iodine 5. Potassium and Acetate 5. Potassium and Acetate 6. Gold and a. 6. Gold and Nitrogen Nitrogen b. BINARY MOLECULAR COMPOUNDS Except for Hydrocarbons (C-H compounds), PREFIXES: 1 - mon(o) NH3, NH4 and H-X (H & halogen) 2 - di 3 - tri NM1 + NM2 4 - tetr(a) Name of 1st non metal Root name of 2nd non metal 5 - pent(a) 6 - hex(a) ADD prefix if >1 atom ADD prefix all the time 7 - hept(a) CHANGE suffix to-IDE 8 - oct(a) 9 - non(a) 10 - dec(a) CCl4 = Carbon tetrachloride P2O5 = Diphosphorous pentoxide Exercise 3: PREFIXES: 1 - mon(o) Name the chemical formulas of these molecular 2 - di compounds aka covalent compounds. 3 - tri 4 - tetr(a) 5 - pent(a) 7. CO 6 - hex(a) 7 - hept(a) 8. N2O 8 - oct(a) 9. NO3 9 - non(a) 10 - dec(a) 10. P2Cl7 11. S2O9 TERNARY IONIC COMPOUNDS 1. MONOATOMIC CATION + POLYATOMIC ANION Ex: Sodium + Nitrite Na+ + NO2- Na1 NO2 → NaNO2 sodium nitrite 2. POLYATOMIC CATION + MONOATOMIC ANION Ex: Ammonium + Sulfide NH4+ + S2- (NH4)2 S1 → (NH4)2S ammonium sulfide Exercise 4: Write and name the chemical formulas of these tertiary ionic compounds. 12. Iron (II) + sulfate 13. Calcium + nitrite 14. Aluminum + borate 15. Hydronium + phosphide 16. Ammonium + chloride RULES IN CHEMICAL FORMULA NAMING AND WRITING (ACIDS & BASES) *YOU’RE  Binary Acid ACIDS (H+) H + monoatomic anion H+ + Cl– H1 Cl1 HCl a. if gaseous Hydrogen chloride Hydogren element–ide b. if liquid or aqueous Hydrochloric acid Hydro – rootname – ic – acid  Ternary Acid “oxy-acid” ACIDS (H+) H + polyatomic anion A. LOWER OXID. NUMBER: ‘ite’= rootname – ous – acid H+ + NO2 – (nitrite) HNO2 Nitr-ous acid _______________________________________ B. HIGHER OXID. NUMBER: ‘ate’ = rootname –ic – acid H+ + NO3 – (nitrate) HNO3 Nitr-ic acid BASES (OH-) Monoatomic cation + OH Polyatomic cation + OH Na+ + OH– NH4+ + OH– NaOH NH4OH sodium hydroxide ammonium hydroxide (OH–) is read as “hydroxide” Exercise 5: Write and name the chemical formulas of these acids and bases. 17. Copper (II)+ hydroxide 18. Hydrogen + Fluorine 19. Barium + Hydroxide 20. Hydrogen + Phosphite 21. Hydrogen + Phosphate 22. Iron (II) + Sulfate THANK YOU!