Chemistry 102

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Chemistry 102

• Dr. Don DeCoste
• 109 Chemistry Annex
• decoste_at_illinois.edu
• 244-5959
• 2-3 pm Mondays and Tuesdays and 3-4 pm Thursdays
• By appointment

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Web Site

• http//www.chem.illinois.edu
• Now includes example exam.
• Electronic homework (1st and 2nd assignments due
  Wednesday, September 9, 9 am)

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Question 1

• Which best describes your current status?
• a) Freshman (1st year)
• b) Sophomore
• c) Junior
• d) Senior
• e) 5th-year senior

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Question 2

• Which best describes your major?
• a) Chemistry or Chemical Engineering
• b) Biology or Life Science
• c) Engineering
• d) Agriculture
• e) Other

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Question 3

• How many significant figures are in the
  measurement 0.030140 liters?
• a) 3
• b) 4
• c) 5
• d) 6
• e) 7

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Question 4

• How many significant figures should be reported?
• a) 1
• b) 2
• c) 3
• d) 4
• e) 5

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Question 5

• You add 82.4 mL of water in a graduated cylinder
  to 25 mL of water in a beaker. How much water
  should you report?
• a) 100 mL (1 significant figure)
• b) 110 mL (2 significant figures)
• c) 110. mL (3 significant figures)
• d) 107 mL (3 significant figures)
• e) 107.4 (4 significant figures)

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Particulate Nature of Matter

• Atom smallest part of an element that is still
  that element (fundamental unit of which elements
  are composed).
• Molecule Two or more atoms joined and acting as
  a unit. (element or compound)

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Daltons Theory

• All matter is made of atoms.
• Atoms of the same element are the same (atoms of
  different elements are different).

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Atomic Element
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Molecular Elements
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Daltons Theory
Compounds are combinations of different atoms. A
given compound always has the same relative
numbers and types of atoms.
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Daltons Theory
Chemical reactions are rearrangements of atoms.
Atoms are not changed in a chemical reaction.
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Macroscopic versus Microscopic