Chemistry

AP Chemistry Name Limiting And Excess Reactants & More 1. When 194g of sulfur dioxide and 88g of oxygen gas react, sulfur trioxide is produced. a. Which reactant is limiting? b. What is the theoretical yield of sulfur trioxide? c. How many grams of the excess reactant will be left? 2. 480 mL of 0.200M copper (II) nitrate reacts with 24.5g of zinc to form 4.89 g copper and zinc nitrate. a. Which reactant is limiting? b. What is the percent yield of copper? c. How much of the excess reactant will be in excess? 3. A dry cleaning agent, (M=146.99 g/mol), that contains C, H, and Cl is a suspected cancer causing agent. When a .250 g sample was studied by combustion analysis, 0.451g of CO2 and 0.0617 g of H2O formed.

Chapter 3 The Mole The Mole: The amount of a substance that contains the same number of ?entities? as 12 grams of Carbon-12 (C-12) 1 mol C-12 = 6.022 x 1023 Carbon atoms 1 mol H20 = 6.022 x 1023 molecules H20 1 mol H20 = 2 mols H and 1 mol O (ratio never changes) Definitions The mole: the SI unit for amount of substance Specifies the # of objects in a fixed mass of substance Avogadro's #: 6.022 x 1023 All isotopes are considered to have the same atomic mass The mass on the periodic table is an average of the masses of the naturally occurring isotopes The atomic mass of an element expressed in amu is numerically the same as the mass of 1 mole of atoms of the element expressed in grams Example:

Unit 1: Sigfigs and Nomenclature AP Chem 2016-2017 Mrs. Han Matter A. Pure Substance: doesn?t change composition, fixed properties 1. Molecule: covalent bond 2. Compound: ionic bond B. Mixture: two or more pure substances 1. Properties change C. States of Matter 1. Solid: strong attraction, low kinetic Energy, constant volume and shape 2. Liquid: constant volume, shape changes 3. Gas: no set volume or shape Energy A. Definition: ability to do work, apply force to make molecules move 1. Kinetic: energy of motion 2. Potential: stored energy due to position 3. ET: total energy is the sum of kinetic and potential B. 1st Law of Thermodynamics 1. Conservation of energy, energy cannot be created or destroyed II. Significant Figures A. Accuracy vs. Precision

F.R.Q. AP US Government Free Response Questions The Basics ? AP Exam 4 F.R.Q. Prompts Each prompt is guided by a theme, and has sub-prompts A); B); C); etc. Total of 100 minutes to complete (double what you had for APUSH short answers!) Worth 50% of your AP Exam!! How do we answer them? Each prompt must be planned and answered in 25 minutes. If you take about 8 minutes to CAREFULLY outline and plan, then you?d have about 17 minutes to write 3 paragraphs (consider that your outline has all the info? so you?d just need to put it into sentences) (1) Laser focus on EXACT prompt (look at hints in the passage; key words, etc..) (2) Define any VOCAB terms

AP Chemistry Unit 2 Moles and Stoich Review Problems 1. If there are 185 grams of C6H14 How many moles of hexane are there? How many atoms of hydrogen are there? How many molecules of hexane are there? 2. Several brands of antacid tablets use aluminum hydroxide to neutralize excess acid. Al(OH)3 (s) + 3 HCl(aq) ? AlCl3 (aq) + 3 H2O(l) Molar masses: 78.01 36.46 133.4 18.02 If .750 g of aluminum hydroxide and 45mL of 1.5M hydrochloric acid are used, what would limit how much aluminum chloride is produced? What is the theoretical yield of aluminum chloride? How much excess reactant is left over?