Review for Bonding Test(Jan 2015) – Remember to read Ch. 7 + 8 some on hydrogen bonding (ch12) to review (and see pictures of) these concepts.

Especially chapter 7 section 2 (pages 210-217), chapter 8 section 1 (pages 240-245),chapter 8 section 3 (pages 253-260),chapter 8 section 4 (pages 261-264), andchapter 12 section 2 (pages 411-414, especially page 413).

(Review chapter 10 section 4 (pages 341-350). For empirical and molecular formulas)

Know the following concepts VERY WELL:

Ionic vs covalent

Polar vs Nonpolar

Electronegativity

Lewis Dot Structures and VSEPR shapes

Bonding

Given two molecules CH2Cl2 and CH4, how can one be nonpolar and the other polar? Which is nonpolar?

Bonding orbitals used & shape: Match with its shape: Nomeclature – name the molecule: Lewis Dot Model:

s shape: ___Line_____H2______

s2shape: _linear______H2O______

sp2shape: ______CH4______

sp3shape: ______BeF2______

p3shape: ______BH3______

p2shape: ______PH3______

p shape: __Line______Cl2______

  1. A covalent bond is created when ______(#) electrons are shared.
  2. A triple covalent bonds has ______(#) electrons shared.
  3. Ammonia (NH3) makes a______shape and is ______(polar or non-polar).
  4. Oxygen has ______(#) pairs of unbonding electrons in a water molecule, these electrons are called ______pairs.

Be able to Draw Lewis Dot Structures for Ionic Compounds, Molecular Compounds and polyatomic ions

Draw Lewis Dot Structures, give their VSEPR shapes and determine if the molecules are polar.

BeCl2NI3ClO3-HClO3

Be able to solve empirical and molecular formula problems

  1. A compound with the following composition has a molar mass of 60.10g/mol: 39.97% carbon; 13.41% hydrogen; 46.62% nitrogen. First find the empirical formula then find the molecular formula.
  1. Naphthalene is a carbon and hydrogen containing compound often used in moth balls. The empirical formula is C5H4 and its molar mass is 128.16g/mol. Find the molecular formula.
  1. Water only has a mass of 18 g/mol and is a liquid at room temperature; N2 and O2 have a greater molar mass (28 g/ mol and 32 g/ mol). Why is water a liquid and the others gases ?

Vocabulary – know definitions and be able to use in the context of a question:

Covalent Bond –

Ionic Bond –

Electron Dot Structures –

Octet Rule –

Electronegativity –

VSEPR

Selected Answers: 1. Two 2. Six 3. Pyramidal, polar 4. Two, lone pairs 5. C2H8N2 6. C10H8

Review for Bonding Test – SAMPLE ANSWERS

Assigned readings: p.240-243, p.253-257, p. 261-270 Chapter 210-215

Know the following concepts VERY WELL:

Why and how atoms ionize To complete an octet or to have the electron configuration of a Nobel gas

Ionic vs covalent Ionic give and take to for ions (metal positive cations, negative non-metal anions, covalent SHARE to complete an octet

Polar vs Nonpolar Polar means lopsided shape (or pointable); Non-polar are balanced or non-lopsided

Water is polar oils are non-polar

Electronegativity if the electronegativity on one element is a lot more than the other the compound forms ions (or is “polared apart”)

Given two molecules CH2Cl2 and CH4, how can one be nonpolar and the other polar? Which is nonpolar?

CH2Cl2 is polar, the chlorine attracts the electrons in bonds better than the hydrogen; CH4 is not lopsided (nonpolar) the hydrogen are distributed evenly around the carbon center.

Bonding orbitals used & shape: Match with its shape: Nomeclature – name the molecule:Electron Dot Model:

s shape: ___Line_____H2___hydrogen______

s2shape: _linear______H2O_water or dihydrogen monoxide______

sp2shape: trigonal planer_CH4__methane or carbon tetra hydride)______

sp3shape: _tetrahedral___BeF2__berylium fluoride______

p3shape: _pyramidal___BH3___Boron hydride______

p2shape: _bent line____PH3__Phosphorus tri hydride______

p shape: __Line______Cl2__Chlorine______

  1. A covalent bond is created when ______(#) electrons are shared.
  2. A triple covalent bonds has ______(#) electrons shared.
  3. Ammonia (NH3) makes a______shape and is ______(polar or non-polar).
  4. Oxygen has ______(#) pairs of unbonding electrons in a water molecule, these electrons are called ______pairs.

Vocabulary – know definitions and be able to use in the context of a question:

Covalent Bond –

Ionic Bond –

Electron Dot Structures –

Octet Rule –

Electronegativity –

VSPER

Selected Answers: 1. Two 2. Six 3. Pyramidal, polar 4. Two, lone pairs