Welcome! (Nov 6th) Chapter 1 time! Please have out on your desk before class: Notes Lab Book Calculator Periodic Table Goggles

Okay, let’s dive in! Review in our book: Chapter 1: Moles, Stoich, Limiting Reagent, % Yield, Empirical Formula, Percent Composition DO NOT worry about solutions or gases yet…that’s where we are headed Chapter 11: Sig figs, Uncertainty in Measurement

Moles and Molar Mass – practice 1 Classic MC problem you should expect! D

Moles and Molar Mass – practice 2

Stoich Refresher… Sugar (C6H12O6) decomposes into two products. Write the equation: How may grams of the product ____ will be produced if you decompose ____ g of sugar?

Percent Yield Do you remember the formula? What is the percent yield of H2O if your experimental yield is ____?

MC Question #3 Calcium carbonate decomposes on heating as shown below. CaCO3  CaO + CO2 When 50 g of calcium carbonate are decomposed, 7 g of calcium oxide are formed. What is the percentage yield of calcium oxide? A. 7% B. 25% C. 50% D. 75% B

MC Question #4 D

Empirical Formulae – MC #5 D

Empirical Formulae Simplest whole-number ratio of elements in a compound Sugar’s molecular formula = C6H12O6 Empirical Formula = ? How do scientists figure it out?

MC Question #6 The percentage by mass of the elements in a compound is C = 72%, H = 12%, O = 16%. What is the mole ratio of C:H in the empirical formula of this compound? A. 1 : 1 B. 1 : 2 C. 1 : 6 D. 6 : 1 B

Lab 5 – Empirical Formula of CuxIy Pre-lab and understanding the procedure first DANGEROUS: Iodine is NOT good to breathe, so all in fume hood! Analytical balance – even finger oil can mess up your results! BE CAREFUL

Homework Day 1 Lab 5 Post-Lab finished for next class WS 1- good review problems More next class!