Unit 4 Exam Review

1. Unit 4 Exam Review The test will consist of 25 multiple choice questions. You will be provided with a periodic table. You will need to bring a #2 pencil and a calculator. You may not share calculators during the test. You will not be allowed to use a phone as a calculator. The test answers will be recorded on a scantron answer document. You may write on the test, but only the scantron answer document will be graded. • The mole concept: • SI unit of a substance • 1 mole = molar mass (from periodic table) • 1 mole = 22.4 L @ STP • 1 mole = 6.02 x 1023 R.P. • Avogadro’s number = 6.02 x 1023 representative particles • Representative Particles: atoms, molecules (covalent), formula units (ionic) • Determine how many atoms are in a compound • Define molar mass with respect to mole concept • Determine molar mass of a compound (will be needed for many mole calculations) • Complete mole calculations • 1-step calculations: • Moles to mass, mass to moles • Moles to volume, volume to moles • Moles to representative particles, representative particle to moles • 2 step calculations: • Mass to volume, volume to mass • Mass to representative particles, representative particles to mass • Volume to representative particles, representative particles to volume • Determine the percent composition by mass for a given compound • Part / whole x 100% = percent composition • Determine molar mass of a hydrate • Calculate the percent composition of water for a hydrate • Recognize hydrate terminology • Hydrate – with water • Anhydrous – without water • Compare and contrast empirical vs. molecular formulas • Determine empirical formulas • Determine molecular formulas