General Chemistry, Zumdahl/munowitz Texts, Chapter 1

Front 1

Define "scientific method"

Back 1

A systematic approach to the investigation of nature, rooted in empirical observation, hypothesis, experiment and theory.

Front 2

Define "measurement"

Back 2

determination of dimensions, extent, amount, and other properties, usually by comparison with a standard quantity.

Front 3

Define "hypothesis"

Back 3

A proposed explanation for a set of observations

Front 4

Define "theory"

Back 4

A model developed to explain a body of prior observations and to predict new phenomena

Front 5

Define "model"

Back 5

Also, a theory. A set of tested hypotheses that gives an overall explanation of some natural phenomenon.

Front 6

Define "natural law"

Back 6

Generally observed behavior that applies to many systems, i.e., the law of the conservation of mass

Front 7

Define "the law of conservation of mass and energy"

Back 7

a physical law deriving from the equivalence of mass and energy, in a system closed to the outside, the total amount of all energy, including mass-energy (E = mc2) is constant.

In CHEMICAL REACTIONS, where mass is not appreciably converted to energy, the law reduces to the more restrictive CONSERVATION OF MASS: total mass is constant. Matter may not be created or destroyed.

Front 8

Define "SI System"

Back 8

Systeme International d'Unites. Widely used for scientific applications, informally, the metric system.

Front 9

List the seven fundamental SI units

Back 9

Length (meter), mass (kilogram), time (second), electric current (ampere), temperature (Kelvin) amount of substance (mole), and luminous intensity (candela). All other units are derived from those seven base quantities.

Front 10

Define "mass"

Back 10

The amount of matter in a sample, defined through Newton's Law ( m equal force divided by acceleration).

Front 11

Define "weight"

Back 11

the force (W) exerted by gravity on an object, proportional to its mass (m). Near the earth's surface the relationship between weight and mass is W = mg, where g equals the standard acceleration due to gravity.

Front 12

Define "uncertainty"

Back 12

doubt concerning the value of a quantity, arising from random error

Front 13

Define "significant figures"

Back 13

The meaningful digits reported for a measured quantity, inclusive of the first uncertain digit. All subsequent digits are considered not significant

Front 14

Define "accuracy"

Back 14

the extent to which a measure value, distinct from precision

Front 15

Define "precision"

Back 15

The extent to which measured values agree among themselves, distinct from accurace. The more precise the measurements, the lower is the random error.

Front 16

Define "random error"

Back 16

An unpredictable fluctuation, sometimes above a median value and sometimes below.

Front 17

Define "systematic error"

Back 17

a persistent, nonrandom discrepancy that does not average to zero over repeated trials.

Front 18

Define "exponential notation"

Back 18

Expresses a number as N x 10 to the m, easily representing very large or very small numbers and displaying significant figures

Front 19

Define "unit factor method"

Back 19

also known as factor-label method, a method of dimensional analysis in which unit factors are used to convert one quantity into another.

Front 20

Define " dimensional analysis"

Back 20

a general approach to computation in which the units of the relevant quantities are used to derive the proper relationship

Front 21

Define " density"

Back 21

1) For bulk matter, the ratio of mass (m) to volume (v):
density is mass over volume.
2) For Quantum mechanics: the point-by-point probability of locating an electron throughout space (proportional to the square of the wave function)

Front 22

Define "matter"

Back 22

The tangible stuff of the universe, anything that has mass and occupies space.

Front 23

Define "states of matter"

Back 23

an aggregation of atoms, molecules, or ions shaped by interparticular forces and often macroscopic in extent, a phase. Solid, liquid, and gas are the most common forms, but there are also intermediate forms such as clusters and liquid crystals.

Front 24

Define "homogeneous mixture"

Back 24

Either made from only one kind of part, or else blended together uniformly. In a homogeneous mixtures (a solution) all components are mixed intimately and uniformly.

Front 25

Define "heterogeneous mixture"

Back 25

made from different parts, as a patchwork. A system containing different phases is said to be heterogeneous, as is a mixture in which the different components are segregated into distinct regions.

Front 26

Define "solution"

Back 26

a homogeneous phase produced by dispersal of a solute throughout a solvent, intermingled thoroughly at the molecular level.

Front 27

Define "pure substance"

Back 27

A pure sample of matter with definite atomic composition and characteristic properties

Front 28

Define "physical change"

Back 28

a change in the form of a substance, but not in the chemical composition

Front 29

Define "distillation"

Back 29

separation of the components in a mixture by selective vaporization and subsequent condensation.

Front 30

Define "filtration"

Back 30

a method of separation used when the mixture consists of a solid and a liquid. The mixture is poured into a mesh, like filter paper, which passes the liquid and retains the solid

Front 31

Define "chromatography"

Back 31

Separation of a mixture into its components, accomplished by differential adsorption onto various media.

Front 32

Define "paper chromatography"

Back 32

All chromatography uses a stationary phase and a mobile phase. the components of the mixture have different affinities for each phase, and will separate out accordingly. In paper chromatography, paper provides the stationary phase.

Front 33

Define "compound"

Back 33

A substance formed from two or more elements in definite proportions.

Front 34

Define "chemical change"

Back 34

a process in which a given substance becomes a new substance or substances with different properties and different composition