General Chemistry

1. General Chemistry CHM 101 John Tyrell

3. Dr. John Tyrell Office: Dobo 227 • Telephone: 962-7299(campus); 793-3361(home) Email: tyrellj@uncw.edu • http://people.uncw.edu/tyrellj/ • Office Hours: Mondays 6:30-7:30 p.m & Wednesdays 2:45-3:45 p.m. and by appointment. Drop ins welcome

4. Grading Policy: • Your grade in this course is based on your performance on the following items: • Hourly exams (there will be three of them): 50%Final exam: 20%Laboratory work: 15%Quizzes : 15% • Labs start next week (not on Monday) • (need lab manual & safety goggles)

5. Keys to Success • Come to class • Mind as well as body • Don’t be bashful • Actively do problems. (keep a notebook) • It’s like a marathon – keep up a steady pace throughout • Cooperation leads to graduation

6. Let’s get started • Chemistry is the study of matter

7. The Study of Chemistry The Molecular Perspective of Chemistry • Matter is the physical material of the universe. • Matter is made up of relatively few elements. • On the microscopic level, matter consists of atoms and molecules. • Atoms combine to form molecules. • Molecules may consist of the same type of atoms or different types of atoms.

8. The Study of Chemistry The Molecular Perspective of Chemistry • In these models, we use red to represent oxygen, white to represent hydrogen, and gray to represent carbon.

9. Classification of Matter States of Matter • Matter can be a gas, a liquid, or a solid. • These are the three states of matter. • Gases have no fixed shape or volume. • Gases can be compressed to form liquids. • Liquids have no shape, but they do have a volume. • Solids are rigid and have a definite shape and volume.

10. Classification of Matter Pure Substances and Mixtures • Atoms consist only of one type of element. • Molecules can consist of more than one type of element. • Molecules can have only one type of atom (an element). • Molecules can have more than one type of atom (a compound). • If more than one compound are found together, then the substance is a mixture.

11. Classification of Matter Pure Substances and Mixtures

12. Classification of Matter Pure Substances and Mixtures • If matter is not uniform throughout, then it is a heterogeneous mixture. • If matter is uniform throughout, it is homogeneous. • If homogeneous matter can be separated by physical means, then the matter is a mixture. • If homogeneous matter cannot be separated by physical means, then the matter is a pure substance. • If a pure substance can be decomposed into something else, then the substance is a compound.

13. Classification of Matter Pure Substances and Mixtures If a pure substance cannot be decomposed into something else, then the substance is an element.

14. Classification of Matter Compounds • Most elements interact to form compounds. • The proportions of elements in compounds are the same irrespective of how the compound was formed. • Law of Constant Composition (or Law of Definite Proportions): • The composition of a pure compound is always the same. • Therefore, if water is decomposed, then there will always be twice as much hydrogen gas formed as oxygen gas.