1.3 Physical and Chemical Properties

Question 1

Physical property

Answer 1

Is a characteristic of matter that is not associated with a change in its chemical composition. Density, color, hardness, melting and boiling point, and electrical conductivity.

Question 2

Physical Change

Answer 2

Is a change in the state or properties of matter without any accompanying change in the chemical identities of the substances contained in the matter. Physical changes are observed when wax melts, when sugar dissolves in coffee, and when steam condenses into liquid water.

Question 3

Chemical property

Answer 3

The ability to change from one type of matter into another (or the inability to change). Examples of chemical properties include flammability, toxicity, acidity, and many other types of reactivity.

Question 4

Chemical change

Answer 4

Always produces one or more types of matter that differ from the matter present before the change. The formation of rust is a chemical change because rust is a different kind of matter than the iron, oxygen, and water present before the rust formed.

Question 5

Intensive property

Answer 5

If the property of a sample of matter does not depend on the amount of matter present. Temperature is an example of an intensive property.

Question 6

Extensive property

Answer 6

If the property depends on the amount of matter present. The mass and volume of a substance are examples of extensive properties.

Question 7

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 degrees Celsius and boils at -188 degrees Celsius. Finely divided metals burn in fluorine with a bright flame. Nineteen grams of fluorine will react with 1.0 gram of hydrogen

Answer 7

physical; chemical; physical; physical; chemical; chemical.

Question 8

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

Answer 8

(a) physical
(b) chemical
(c) chemical
(d) physical
(e) physical

Question 9

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

Answer 9

(a) chemical
(b) physical
(c) physical
(d) chemical
(e) physical

Question 10

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?

Answer 10

Physical

Question 11

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?

Answer 11

Chemical change

Question 12

Identify the following properties as either extensive or intensive
(a) volume
(b) temperature
(c) humidity
(d) heat
(e) boiling point

Answer 12

(a) extensive
(b) intensive
(c) intensive
(d) extensive
(e) intensive

Question 13

Explain the difference between extensive properties and intensive properties.

Answer 13

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.

Question 14

The density (d) of a substance is an intensive property that is defined as the ration of its mass (m) to its volume (V).
density = mass/volume d= m/v
Considering that mass and volume are both extensive properties, explain their ratio, density, is intensive.

Answer 14

Being extensive properties, both mass and volume are directly proportional to the amount of substance under study. Dividing one extensive property by another will affect “cancel” this dependence on amount, yielding a ratio that is independent of amount (an intensive property).