Book: Ch. 1

Question 1

Chemistry is the study of _____. Matter is _____. The composition of matter is _____.

Answer 1

1. matter and its properties, the changes that matter undergoes, and the energy associated with those changes
2. the “stuff” of the universe: air, glass, planets, students—anything that has mass and volume.
3. the types and amounts of simpler substances that make it up. A substance is a type of matter that has a defined, fixed composition.

Question 2

The states of matter are _____

Answer 2

solid, liquid, gas

Question 3

Properties of matter are _____. Physical properties of matter are _____. Chemical properties are _____.

Answer 3

1. The characteristics that give each substance its unique identity.
2. characteristics a substance shows by itself, without changing into or interacting with another substance. These properties include melting point, electrical conductivity, and density.
3. characteristics a substance shows as it changes into or interacts with another substance (or substances). Chemical properties include flammability, corrosiveness, and reactivity with acids.

Question 4

A physical change occurs when _____, and a chemical change (aka a chemical reaction) occurs when _____

Answer 4

1. a substance alters its physical properties, not its composition.
2. a substance (or substances) is converted into a different substance (or substances)

Question 5

We study _____ changes in matter to understand their _____ causes.

Answer 5

1. observable

2. unobservable

Question 6

Energy is often defined as _____. The total energy an object possesses is _____. Potential energy is _____. Kinetic energy is the energy due to _____.

Answer 6

1. the ability to do work
2. the sum of its potential energy and its kinetic energy
3. the energy due to the position of the object relative to other objects
4. the motion of the object

Question 7

1. When energy is converted from one form to the other, it is _____, not _____.
2. Situations of lower energy (more stable) are _____ over situations of higher energy (less stable).

Answer 7

1. conserved; destroyed

2. favored

Question 8

Our prehistoric ancestors survived through _____, gradually learning which types of stone were hard enough to shape others, which plants were edible and which poisonous, and so forth. Unlike them, we employ the _____.

Answer 8

1. trial and error
2. quantitative theories of chemistry to understand materials, make better use of them, and create new ones: specialized drugs, advanced composites, synthetic polymers, and countless others (Figure 1.5)

Question 9

scientific method is _____

Answer 9

a process involving creative propositions and tests aimed at objective, verifiable discoveries. There is no single procedure, and luck often plays a key role in discovery. In general terms, the scientific approach includes the following parts (Figure 1.6):

Question 10

The scientific method is a process designed to _____.

Answer 10

explain and predict phenomena

Question 11

Observations lead to _____. When repeated with no exceptions, observations may be expressed as _____.

Answer 11

1. hypotheses about how or why a phenomenon occurs

2. a natural law

Question 12

_____ are tested by controlled experiments and revised when necessary.

Answer 12

Hypotheses

Question 13

If reproducible data support a hypothesis, _____ can be developed to explain the observed phenomenon. A good model _____.

Answer 13

1. a model (theory)

2. predicts related phenomena but must be refined whenever conflicting data appear

Question 14

density is an example of _____ units. It is found via the formula _____

Answer 14

1. derived

2. mass/volume

Question 15

Temperature (T) is _____

Answer 15

a measure of how hot or cold one object is relative to another.

Question 16

Heat is _____

Answer 16

the energy that flows from the object with the higher temperature to the object with the lower temperature. When you hold an ice cube, it feels like the “cold” flows into your hand, but actually, heat flows from your hand to the ice.

Question 17

In the laboratory, we measure temperature with _____

Answer 17

a thermometer, a narrow tube containing a fluid that expands when heated.

Question 18

The SI base unit of temperature is _____

Answer 18

the kelvin (K, with no degree sign).

Question 19

The Celsius scale sets water’s freezing point at _____ and its boiling point (at normal atmospheric pressure) at _____. Thus, the size of a Celsius degree is _____.

Answer 19

1. 0 C
2. 100 C
3. 1/100 of the difference between the freezing and boiling points of water

Question 20

T (in K) = _____

Answer 20

T (in C) + 273.15

Question 21

T (in C) = _____

Answer 21

T (in K) - 273.15 = (T (in F) - 32)/1.8

Question 22

T (in F) = _____

Answer 22

1.8 T (in C) + 32

Question 23

extensive properties are _____. Examples include _____

Answer 23

1. dependent on the amount of substance present

2. Mass and volume, heat,

Question 24

intensive properties are _____. Examples include _____

Answer 24

1. independent of the amount of substance

2. density, temperature

Question 25

We generally assume the uncertainty of a value is _____

Answer 25

the rightmost digit; so 20.305 would have uncertainty of + or - 0.001

Question 26

The procedure for determining the significant figures of a measurement is _____

Answer 26

1. Make sure the measurement has a decimal point.
2. Start at the left, and move right until you reach the first nonzero digit.
3. Count that digit and every digit to its right as significant.

However…

• If there is a decimal point and the zeros lie either after or before it, they are significant: 1.1300 g has five significant figures and 6500. has four.
• If there is no decimal point, we assume that the zeros are not significant, unless exponential notation clarifies the quantity: 5300 L is assumed to have two significant figures, but 5.3003103 L has four, 5.303x10^3 L has three, and 5.33x10^3 L has two.
• A terminal decimal point indicates that zeros are significant: 500 mL has one significant figure, but 500. mL has three (as do 5.003x10^2 mL and 0.500 L).

Question 27

The general rule for rounding is that _____

Answer 27

the least certain measurement sets the limit on certainty for the entire calculation and determines the number of significant figures in the final answer.

Question 28

The rule for sig. figs. for multiplication and division is _____. For addition and subtraction, it is _____

Answer 28

1. The answer contains the same number of significant figures as there are in the measurement with the fewest significant figures.
2. The answer has the same number of decimal places as there are in the measurement with the fewest decimal places.

Question 29

Exact numbers are those with _____. Unlike a measured quantity, exact numbers _____

Answer 29

1. no uncertainty associated with them

2. do not limit the number of significant figures in a calculation.

Question 30

Precision, or reproducibility, refers to _____

Answer 30

how close the measurements in a series are to each other

Question 31

accuracy refers to _____

Answer 31

how close each measurement is to the actual value

Question 32

Define systematic error and random error.

Answer 32

1. Systematic error produces values that are either all higher or all lower than the actual value. This type of error is part of the experimental system, often caused by a faulty device or by a consistent mistake in taking a reading.
2. Random error, in the absence of systematic error, produces values that are higher and lower than the actual value. Random error always occurs, but its size depends on the measurer’s skill and the instrument’s precision.

Question 33

Precise measurements have _____ random error, and Accurate measurements have _____ systematic error and, generally, _____ random error. In some cases, when many measurements have a _____ random error, the average may still be accurate.

Answer 33

1. low
2. low
3. low
4. high

Question 34

Systematic error can be taken into account through _____

Answer 34

calibration