Chemistry – Study Guide for 2nd Trimester Exam (Chapters 9 – 11.1)

Chapter 9 – Chemical Names and Formulas

9.1 – Naming Ions

  • When the metals in Groups 1A, 2A, and 3A lose electrons, they form cations with positive charges equal to their group number.
  • The charge of any ion of a Group A nonmetal is determined by subtracting 8 from the group number.
  • The charges of cations of many transition metal ions must be determined from the number of electrons lost. When a cation can have more than one ionic charge, a Roman numeral is used in the name to indicate the charge.
  • The names of most polyatomic anions end in –ite or –ate.

9.2 – Naming and Writing Formulas for Ionic Compounds

  • The name of a binary ionic compound is the cation name followed by the anion name.
  • To write the formula for a binary ionic compound, write the symbol for the cation and then the anion. Then balance the charges.
  • To write formulas for compounds containing polyatomic ions, write the symbol for the metal ion followed by the formula for the polyatomic ion and balance the charges.
  • To name a compound containing a polyatomic ion, state the cation first and then the anion.

9.3 – Naming and Writing Formulas for Molecular Compounds

  • Prefixes show how many atoms of each element are present in a molecule of a binary compound.
  • To write the formula for a binary molecular compound, write the symbols for the elements and use the prefixes to determine the subscripts. Omit mono- for a single atom.

9.4 – Naming and Writing Formulas for Acids and Bases

  • An acid is a combination of a monatomic or polyatomic anion with sufficient hydrogen atoms to make the compound electrically neutral. Acids are names as shown in Table 9.5.
  • A base is a combination of a cation with as many hydroxide ions as are needed to make the compound electrically neutral. Bases are named in the same way as other ionic compounds.

9.5 – The Laws Governing Formulas and Names

  • The ways that compounds form are summed up in two laws: the law of definite proportions and the law of multiple proportions.
  • To name a compound or write its formula, follow the flowcharts in Figures 9.20 and 9.22 to the correct name or formula.

Chapter 9 Vocabulary:

Chemistry – Study Guide for 2nd Trimester Exam (Chapters 9 – 11.1)

  • Acid
  • Base
  • Binary Compound
  • Law of Definite Proportions
  • Law of Multiple Proportions
  • Monatomic Ion
  • Polyatomic Ion

Chemistry – Study Guide for 2nd Trimester Exam (Chapters 9 – 11.1)

Chapter 10 – Chemical Quantities

10.1 – The Mole: A Measurement of Matter

  • Three methods for measuring the amount of a substance are by count, by mass, and by volume.
  • A mole of any substance always contains Avogadro’s number of representative particles, or 6.02 x 1023 representative particles.
  • The atomic mass of an element expressed in grams is the mass of a mole of the element.
  • To calculate the molar mass of a compound, find the number of grams of each element contained in one mole of the compound. Then add the masses of the elements in the compound.

10.2 – Mole-Mass and Mole-Volume Relationships

  • The molar mass of an element or compound is the conversion factor for converting between the mass and the number of moles of a substance.
  • One mole of any gas occupies a volume of 22.4L at standard temperature and pressure. One mole of any substance contains Avogadro’s number of particles, so 22.4L of any gas at STP contains 6.02 x 1023 representative particles of that gas.

10.3 – Percent Composition and Chemical Formulas

  • To determine the percent by mass of any element in a given compound, divide the element’s mass by the mass of the compound and multiply by 100%
  • An empirical formula of a compound is the simplest whole-number ratio of atoms of the elements in the compound.
  • The molecular formula of a compound is either the same as its experimentally determined empirical formula, or it is a simple whole-number multiple of it.

Chapter 10 Vocabulary:

Chemistry – Study Guide for 2nd Trimester Exam (Chapters 9 – 11.1)

  • Avogadro’s Hypothesis
  • Avogadro’s Number
  • Empirical Formula
  • Molar Mass
  • Mole
  • Percent Composition
  • Representative Particle
  • Standard Temperature and Pressure (STP)

Chemistry – Study Guide for 2nd Trimester Exam (Chapters 9 – 11.1)

Key Equations:

Chapter 11 – Chemical Reactions

11.1 – Describing Chemical Reactions

  • To write a word equation, write the names of the reactants to the left of the arrow separated by plus signs; write the names of the products to the right of the arrow, also separated by plus signs.
  • To write a skeleton equation, write the formulas for the reactants to the left of the yields sign and the formulas for the products to the right.
  • After writing the skeleton equation, use coefficients to balance the equation so that is obeys the law of conservation of mass.

Chapter 11 Vocabulary:

  • Activity Series
  • Balanced Equation
  • Catalyst
  • Chemical Equation
  • Coefficients
  • Combination Reaction
  • Combustion Reaction
  • Complete Ionic Equation
  • Decomposition Reaction
  • Double-Replacement Reaction
  • Net Ionic Equation
  • Single-Replacement Reaction
  • Skeleton Equation
  • Spectator Ion