quimica de chang

CHAPTER 1
CHEMISTRY: THE STUDY OF CHANGE
Problem Categories
Biological: 1.24, 1.48, 1.69, 1.70, 1.78, 1.84, 1.93, 1.95, 1.96, 1.97, 1.105.
Conceptual: 1.3, 1.4, 1.11, 1.12, 1.15, 1.16, 1.54, 1.62, 1.89, 1.101, 1.103.
Environmental: 1.70, 1.87, 1.89, 1.92, 1.98.
Industrial: 1.51, 1.55, 1.72, 1.81, 1.91.
Difficulty Level
Easy: 1.3, 1.11, 1.13, 1.14, 1.15, 1.21, 1.22, 1.23, 1.24, 1.25,1.26, 1.29, 1.30, 1.31, 1.32, 1.33, 1.34, 1.54, 1.55, 1.63,
1.64, 1.77, 1.80, 1.84, 1.89, 1.91.
Medium: 1.4, 1.12, 1.16, 1.35, 1.36, 1.37, 1.38, 1.39, 1.40, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, 1.50,
1.51, 1.52, 1.53, 1.56, 1.57, 1.59, 1.60, 1.61, 1.62, 1.70, 1.71, 1.72, 1.73, 1.74, 1.75, 1.76, 1.78, 1.79, 1.81, 1.82, 1.83,
1.85, 1.94, 1.95, 1.96, 1.97, 1.98.
Difficult: 1.58,1.65, 1.66, 1.67, 1.68, 1.69, 1.86, 1.87, 1.88, 1.90, 1.92, 1.93, 1.99, 1.100, 1.101, 1.102, 1.103, 1.104,
1.105, 1.106.
1.3

(a)

Quantitative. This statement clearly involves a measurable distance.

(b)

Qualitative. This is a value judgment. There is no numerical scale of measurement for artistic
excellence.

(c)

Qualitative. If the numerical values for the densities of ice andwater were given, it would be a
quantitative statement.

(d)

Qualitative. Another value judgment.

(e)

Qualitative. Even though numbers are involved, they are not the result of measurement.

1.4

(a)

hypothesis

1.11

(a)

Chemical property. Oxygen gas is consumed in a combustion reaction; its composition and identity are
changed.

(b)

Chemical property. The fertilizeris consumed by the growing plants; it is turned into vegetable matter
(different composition).

(c)

Physical property. The measurement of the boiling point of water does not change its identity or
composition.

(d)

Physical property. The measurement of the densities of lead and aluminum does not change their
composition.

(e)

Chemical property. When uranium undergoes nucleardecay, the products are chemically different
substances.

(a)

Physical change. The helium isn't changed in any way by leaking out of the balloon.

(b)

Chemical change in the battery.

(c)

Physical change. The orange juice concentrate can be regenerated by evaporation of the water.

(d)

Chemical change. Photosynthesis changes water, carbon dioxide, etc., into complex organic matter.(e)

Physical change. The salt can be recovered unchanged by evaporation.

1.12

(b)

law

(c)

theory

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2

CHAPTER 1: CHEMISTRY--THE STUDY OF CHANGE

1.13

Li, lithium; F, fluorine; P, phosphorus; Cu, copper; As, arsenic; Zn, zinc; Cl, chlorine; Pt, platinum;
Mg, magnesium; U, uranium; Al, aluminum; Si, silicon; Ne, neon.

1.14

(a)
(f)

KPu

1.15

(a)

element

1.16

(a)
(d)
(g)

homogeneous mixture
homogeneous mixture
heterogeneous mixture

1.21

density =

1.22

Strategy: We are given the density and volume of a liquid and asked to calculate the mass of the liquid.
Rearrange the density equation, Equation (1.1) of the text, to solve for mass.

(b)
(g)

Sn
S

(c)
(h)

(b)

compound

(d)(i)

Cr
Ar

(b)
(e)

(c)

(e)

B
Hg

element

(d)

element
heterogeneous mixture

(c)
(f)

Ba

compound
compound
homogeneous mixture

mass
586 g
=
= 3.12 g/mL
volume
188 mL

density =

mass
volume

Solution:
mass = density × volume
mass of ethanol =

1.23

? °C = (°F − 32°F) ×

0.798 g
× 17.4 mL = 13.9 g
1 mL

5°C
9°F

5°C
= 35°C
9°F
5°C(12 − 32)°F ×
= − 11°C
9° F
5°C
(102 − 32)°F ×
= 39°C
9°F
5°C
(1852 − 32)°F ×
= 1011°C
9°F
9° F ⎞
⎛
⎜ °C × 5°C ⎟ + 32°F
⎝
⎠

(a)

? °C = (95 − 32)°F ×

(b)

? °C =

(c)

? °C =

(d)

? °C =

(e)

? °F =

9° F ⎞
⎛
? °F = ⎜ −273.15 °C ×
+ 32°F = − 459.67°F
5
°C ⎟⎠
⎝

1.24

Strategy: Find the appropriate equations for converting between Fahrenheit...