1.3: Physical and Chemical Properties
Chemistry: Atoms First 2e
1: Essential Ideas
1.3: Physical and Chemical Properties
26. Classify the six underlined properties in the following paragraph as chemical or physical:
Fluorine is a pale yellow gas that reacts with most substances. The free element melts at –220 C
and boils at –188 C. Finely divided metals burn in fluorine with a bright flame. Nineteen grams
of fluorine will react with 1.0 gram of hydrogen.
Solution
physical; chemical; physical; physical; chemical; chemical
27. Classify each of the following changes as physical or chemical:
(a) condensation of steam
(b) burning of gasoline
(c) souring of milk
(d) dissolving of sugar in water
(e) melting of gold
Solution
(a) physical; (b) chemical; (c) chemical; (d) physical; (e) physical
28. Classify each of the following changes as physical or chemical:
(a) coal burning
(b) ice melting
(c) mixing chocolate syrup with milk
(d) explosion of a firecracker
(e) magnetizing of a screwdriver
Solution
(a) chemical; (b) physical; (c) physical; (d) chemical; (e) physical
29. The volume of a sample of oxygen gas changed from 10 mL to 11 mL as the temperature
changed. Is this a chemical or physical change?
Solution
physical
30. A 2.0-liter volume of hydrogen gas combined with 1.0 liter of oxygen gas to produce 2.0
liters of water vapor. Does oxygen undergo a chemical or physical change?
Solution
Two different elements combine to form a different substance. The change is chemical.
31. Explain the difference between extensive properties and intensive properties.
Solution
The value of an extensive property depends upon the amount of matter being considered,
whereas the value of an intensive property is the same regardless of the amount of matter being
considered.
32. Identify the following properties as either extensive or intensive.
(a) volume
(b) temperature
(c) humidity
(d) heat
(e) boiling point
Solution
(a) extensive; (b) intensive; (c) intensive; (d) extensive; (e) intensive
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