Chapter 1 Chemical Foundations

Question 0

Scientific Method (definition)

Answer 0

The process that lies at the center of scientific inquiry.

Question 1

Fundamental Concepts of Chemistry

Answer 1

1. Matter is composed of various types of atoms.

2. One substance changes to another by reorganizing the way the atoms are attached to each other.

Question 2

Scientific Method (steps)

Answer 2

1. Make observations (collecting data)
2. Making a prediction (formulating a hypothesis)
3. Doing experiments to test the prediction (testing the hypothesis)

Question 3

Measurement

Answer 3

A quantitative observation that involves both a number and a unit.

Question 4

Hypothesis

Answer 4

A possible explanation for an observation.

Question 5

Theory (Model)

Answer 5

A set of tested hypotheses that gives an overall explanation of some natural phenomenon.

Question 6

Natural Law

Answer 6

Generally observed behavior formulated into a statement.

Question 7

Law of Conservation of Mass

Answer 7

The observation that the total mass of materials is not affected by a chemical change. Mass is neither created nor destroyed.

Question 8

SI System (International System)

Answer 8

An international agreement set up a system of units. It’s based on the metric system.

Question 9

Mass

Answer 9

A measure of resistance of an object to change in it’s state of motion. It is measured by the force necessary to give a object a certain acceleration.

Question 10

Weight

Answer 10

The force that gravity exerts on an object to measure it’s masses.

Question 11

Certain Digits

Answer 11

Numbers that remain the same regardless of who makes the measurement.

Question 12

Uncertain Digits

Answer 12

Number that must be estimated (varies). Report a measurement by recording all the certain digits plus the first uncertain digit.

Question 13

Uncertainty

Answer 13

Any measurement involves estimates and cannot be exactly reproduced.

Question 14

Significant Figures

Answer 14

Recording the certain digits and the estimated number. Uncertainty of the estimated number is assumed to be +-1.

Question 15

Accuracy

Answer 15

The agreement of a particular value with the true value.

Question 16

Precision

Answer 16

The degree of agreement among several measurements of the same quantity. It reflects the reproducibility of a given type of measurement.

Question 17

Random Error (Indeterminate Error)

Answer 17

A measurement has an equal probability of being high or low. Occurs in stigma ting the value of the last digit.

Question 18

Systematic Error (Determinate Error)

Answer 18

A measurement is either always high or always low.

Question 19

Rules for Counting Significant Figures in Mathematical Operations

Answer 19

1. Multiplication/Division- Sig Fig is the same number as the least precise measurement in the calculation.
2. Addition/Subtraction- Same number of decimal places as the least specific measurement.

Question 20

Unit Factor Method (Dimensional Analysis)

Answer 20

Unit conversions from English to metric systems.

Question 21

Temperature

Answer 21

Tk(kelvin)=Tc(Celsius)+273.15
Tc=Tk-273.15

Tc=(Tf(Fahrenheit)-32F)(5C/9F)
Tf=Tc(9F/5C)+32F

Question 22

Density

Answer 22

The mass of substance per unit volume of the substance.

D=Mass/Volume

Question 23

Matter

Answer 23

Anything occupying space and having mass. Exists as a solid, liquid, or gas.

Question 24

Mixture

Answer 24

Variable composition.

Question 25

Homogeneous

Answer 25

Visibly indistinguishable parts; a solution.

Question 26

Heterogeneous

Answer 26

Visibly distinguishable parts that can be separated.

Question 27

Solution

Answer 27

A homogenous mixture.

Question 28

Pure Substance

Answer 28

Constant composition, such as H2O.

Question 29

Physical Changes

Answer 29

Boiling/freezing changes state (liquid/gas/solid)

Question 30

Distillation

Answer 30

Separation of mixture components (volatility) through heat.

Question 31

Filtration

Answer 31

Used with a solid/liquid mixture in a mesh filter.

Question 32

Chromatography

Answer 32

A system employing a mobile and stationary phrase to separate mixtures.

Question 33

Paper Chromatography

Answer 33

Strip of filter paper used for the stationary phrase with a drop of mixture that is dipped into a liquid.

Question 34

Compound

Answer 34

Substance with constant composition that can be broken down into elements chemically.

Question 35

Chemical Change

Answer 35

A given substance becomes a new substance with different properties/compositions.

Question 36

Elements

Answer 36

Substances that cannot be decomposed into simpler substances.