Announcements Textbook homework due Friday in discussion (pg. 16) Be respectful – no electronics please! Announcements Textbook homework due Friday in discussion (pg. 16) Electronic HW #1 (Lon-Capa) Wednesday 10:00 pm Pre & Post-lecture Assignments (Lon-Capa) 8:00 am Tuesday & Thursday Lab write-ups must be your own. What to memorize for exam.

Office Hours Today after Lecture (Chemistry Library) Tomorrow 1:30-3 pm (2026 CA) Review Tomorrow 3:00 pm (1025 CA) Thursday 12-1 pm (2026 CA) and after lecture

By the Exam… Know the polyatomic ions and charges (Bottom of periodic practice table). Know common ions and symbols (Should already be labeled on your periodic table). Know covalent prefixes (Table 5.3).

Exam Info Evening Exams 7:00 pm Emphasis is on understanding First one on Sept. 25 Conflict exam Same Day 5:00 pm Emphasis is on understanding

Exam Info 40% Basic Knowledge & Skills 40-50% Application Questions (Pre/Post-lecture questions, book problems) 40-50% Application Questions (Lon-Capa homework questions, lab questions, lecture demonstrations) 10-20% New Problems (Same material, but connected in different ways, or extensions of other problems)

Exam Info 15 Multiple Choice Questions 2 Multi-part free response questions You will be asked to explain. You will be asked questions that link multiple topics together. You will be asked questions that you have not seen before that test your understanding and reasoning skills.

Everybody Writes You have a pile of 100.0 grams of dimes. You want a pile of pennies that has the same number of coins as the dimes pile. What mass of pennies do you need? You have a sample of 10.0 grams of aluminum. You want a sample of copper that has the same number of atoms as this aluminum. What mass of copper do you need? What information do you need to solve each of these problems? How would you use that information?

----------------------------------------- You have a pile of 100.0 grams of dimes. You want a pile of pennies that has the same number of coins as the dimes pile. What mass of pennies do you need? Mass of a dime is 2.6 grams. Mass of a penny is 3.1 grams ----------------------------------------- Mass ratio of a dime to a penny is 1:1.2.

You have a sample of 10. 0 grams of aluminum You have a sample of 10.0 grams of aluminum. You want a sample of copper that has the same number of atoms as this aluminum. What mass of copper do you need?

Periodic Table

Clicker #1 Select the sample that has the lowest mass. 1.0 mol silicon 1.0 mol nitrogen gas 1.0 mol oxygen gas All three of the samples (a. – c.) above have approximately the same mass. Only two of the samples (a. – c.) above have approximately the same mass.

Clicker #2 Which sample contains a greater number of atoms? 10.0 g Cu or 10.0 g Al A) 10.0 g Cu B) 10.0 g Al

Everybody Writes You have 10.0 grams of aluminum. What mass of copper has same number of atoms as 10.0 grams of aluminum?

What is incorrect about the following set-up?  

Clicker #3 How many total atoms are present in 10.0 grams aluminum chloride (AlCl3, molar mass = 133.3 g/mol)? 0.0750 atoms 4.52×1022 atoms 9.65×1022 atoms 1.81×1023 atoms 1.93×1023 atoms

Joke What do you have when you see a mole of moles digging a mole of holes? A bunch of molasses