CHEM 201: Atomic and Ionic Bonding, Nomenclature, and Composition of Compounds
CHEM 201: Atomic and Ionic Bonding, Nomenclature, and Composition of Compounds
Overview
- This document covers atomic and ionic bonding, compound nomenclature, and composition of various chemical compounds.
Classifying Compounds and Acids
Example Exercise: Classifying Compounds and Acids (Solution)
- Classify each compound as:
- Binary ionic compound
- Ternary ionic compound
- Binary molecular compound
- Binary acid
- Ternary oxyacid
- Given Compounds:
- a. Calcium oxide (CaO) - Binary ionic compound
- b. Sulfur dioxide (SO2) - Binary molecular compound
- c. Silver chromate (Ag2CrO4) - Ternary ionic compound
- d. Hydrofluoric acid (HF(aq)) - Binary acid
- e. Carbonic acid (H2CO3(aq)) - Ternary oxyacid
Classifying Compounds and Acids (Practice Exercise)
- Classify each compound:
- a. Carbon disulfide (CS2) - Binary molecular compound
- b. Lithium dichromate (Li2Cr2O7) - Ternary ionic compound
- c. Magnesium iodide (MgI2) - Binary ionic compound
- d. Nitric acid (HNO3(aq)) - Ternary oxyacid
- e. Hydrochloric acid (HCl(aq)) - Binary acid
Classifying Cations and Anions
Example Exercise: Classifying Ions (Solution)
- Classify each ion as:
- Monoatomic cation
- Monoatomic anion
- Polyatomic cation
- Polyatomic anion
- Given Ions:
- a. Barium ion (Ba2+) - Monoatomic cation
- b. Chloride ion (Cl–) - Monoatomic anion
- c. Ammonium ion (NH4+) - Polyatomic cation
- d. Carbonate ion (CO3^2–) - Polyatomic anion
- Provide the formula for each monoatomic cation:
- a. Barium ion - Ca2+
- b. Cobalt(II) ion - Co2+
- Provide the formula for each monoatomic anion:
- a. Fluoride ion - F–
- b. Oxide ion - O2–
Polyatomic Ions
- Provide systematic names for polyatomic oxyanions:
- a. Carbonate ion (CO3^2–) - Carbonate
- b. Chromate ion (CrO4^2–) - Chromate
- c. Chlorite ion (ClO2–) - Chlorite
- d. Hydrogen sulfate ion (HSO4–) - Hydrogen sulfate
- Write the chemical formula for each binary compound:
- a. Copper(I) oxide (Cu+ and O2–) - Cu2O
- b. Cadmium oxide (Cd2+ and O2–) - CdO
- c. Cobalt(III) oxide (Co3+ and O2–) - Co2O3
- Write the chemical formula for each ternary compound:
- a. Calcium carbonate (Ca2+ and CO3^2–) - CaCO3
- b. Calcium hydroxide (Ca2+ and OH–) - Ca(OH)2
- c. Calcium phosphate (Ca2+ and PO4^3–) - Ca3(PO4)2
Determining Ionic Charge in a Compound
Example Exercise: Determining Ionic Charge in a Compound (Solution)
- Charge on an oxide ion is -2.
- Find the ionic charge for iron in hematite (Fe2O3): The charge on iron is +3.
Example Exercise: Determining Ionic Charge in a Compound (Solution)
- To find the ionic charge for iron in Fe3(PO4)2:
- Given that the phosphate ion carries a charge of -3, the charge for iron must be +3.
Naming Ionic Compounds
Example Exercise: Names of Binary Ionic Compounds (Solution)
- Provide systematic names for binary ionic compounds:
- a. Zinc oxide (ZnO)
- b. Tin(II) fluoride (SnF2)
- Write formulas for binary ionic compounds:
- a. Lithium fluoride - LiF
- b. Lead(II) sulfide - PbS
- To predict chemical formulas, compare elements that differ in similar compounds:
- Given Aluminum oxide (Al2O3), predict:
- a. Gallium oxide - Ga2O3
- b. Aluminum sulfide - Al2S3
Naming Acids
Example Exercise: Names of Binary Acids (Solution)
- Binary acids are named as hydro– plus the nonmetal stem plus –ic acid.
- The IUPAC systematic name for HF(aq) is hydrofluoric acid.
Example Exercise: Names of Ternary Oxyacids (Solution)
- Ternary oxyacids are named as –ic acids or –ous acids depending on the related anions.
- The IUPAC systematic name for H3PO4 is phosphoric acid.
Periodic Table and Electron Configuration
Example Exercise: Electron Configuration and the Periodic Table
- Refer to a periodic table to predict the electron configuration:
- a. Phosphorus (P) - 1s² 2s² 2p⁶ 3s² 3p³
- b. Cobalt (Co) - [Ar] 3d⁷ 4s²
Example Exercise: Valence Electrons and the Periodic Table (Solution)
- Predict the number of valence electrons for:
- a. Sodium (Na) - 1 valence electron
- b. Aluminum (Al) - 3 valence electrons
- c. Sulfur (S) - 6 valence electrons
- d. Xenon (Xe) - 8 valence electrons
Example Exercise: Ionization Energy and the Periodic Table
- Ionization energy increases as we move up a group and across a period:
- Compare:
- a. Li or Na - Li has a higher ionization energy.
- b. O or F - O has lower ionization energy than F.
Example Exercise: Predicting Ionic Charges of Cations
- Predict the ionic charge for the sodium ion (Na⁺):
- Sodium is in group 1, hence Na⁺ has a charge of +1.
Example Exercise: Predicting Ionic Charges of Anions
- Predict the ionic charge for the chloride ion (Cl–):
- Chlorine is in group 17, hence Cl– has a charge of -1.
Example Exercise: Predicting Isoelectronic Ions
- Predict which ions are isoelectronic with argon:
- a. K⁺ - Isoelectronic with argon
- b. Br– - Isoelectronic with argon
- c. Ca²⁺ - Isoelectronic with argon
- d. O²– - Not isoelectronic with argon
Example Exercise: Electron Configuration of Ions
- Write electron configuration using core notation:
- a. Fe³⁺ - [Ar] 3d⁵
- b. Se²– - [Ar] 3d¹⁰ 4s² 4p⁶
Worked Examples Transactions
Worked Example: Calculating a Frequency from a Wavelength
- Wavelength (436 nm) corresponds to frequency.
- Utilize the relationship: c =
u imes ext{wavelength} where c is the speed of light (3.0 x10^8 m/s) and
u is frequency.
Worked Example: Calculating the Energy of a Photon from Its Frequency
- The energy of a photon is calculated using: E = hv
- Where h is Planck's constant (6.626 x10^(-34) J·s) and v is frequency.
Worked Example: Using Quantum Numbers to Identify an Orbital
- Quantum numbers detail the properties of orbitals:
- Principal quantum number (n) - shell number.
- Angular momentum quantum number (l) - subshell designation.
- For quantum numbers n = 3, l = 1, mℓ = 1, it indicates a p-orbital in the third shell.
Worked Example: Assigning Quantum Numbers to an Orbital
- For a 4p orbital, the principal quantum number is n = 4 and l = 1:
- Possible quantum number combinations are (4, 1, -1), (4, 1, 0), (4, 1, +1).
Worked Example: Assigning a Ground-State Electron Configuration to an Atom
- For Arsenic (As, Z = 33):
- Ground-state electron configuration is: [Ar] 4s² 3d¹⁰ 4p³.
- Diagram indicates electrons with up and down arrows.
Worked Example: Identifying an Atom from Its Ground-State Electron Configuration
- Given electron configuration leads to the determination of the atom:
- Identify based on electron configuration and atomic number calculations.
Practice Questions
Question 1: What is the chemical name of K2O?
- A) dipotassium oxygen
- B) potassium oxide (Correct Answer)
- C) potasside oxygen
- D) potassium oxygen
- A) CaPO4
- B) Ca2PO4
- C) Ca3PO4
- D) Ca3(PO4)2 (Correct Answer)
- A) NH4S (Correct Answer)
- B) (NH4)2S
- C) (NH4)S2
- D) (NH4)2S3
Question 4: Which of the following is a binary compound?
- A) sodium perchlorate
- B) sodium chlorate
- C) sodium hypochlorite
- D) sodium chloride (Correct Answer)
Question 5: The compound HClO is called?
- A) hydrochloric acid
- B) hypochlorous acid (Correct Answer)
- C) perchloric acid
- D) hyperchloric acid
Question 6: Which of the following aqueous acids does not have the -ic ending?
- A) H2SO4(aq)
- B) HF(aq) (Correct Answer)
- C) HCN(aq)
- D) HClO2(aq)