Exam 1: Chapters 1, 2 and 3 Lecture Notes Flashcards
What is chemistry
The study of the composition and structure of materials and of the changes that matter undergoes
What is matter
Anything that occupies space and has mass
What characteristics of matter change during a reaction
Composition, structure, properties
What is green chemistry
Utilizing a set of principles that encourages alternative ways of generating new and existing chemical products without unnecessary risk to human health and population
What is the purpose of the scientific method
Experiments must be done in a controlled way so that results can be reproduced
What is a hypothesis
a statement that tries to explain something in a common way
What saying was Louis Pasteur known for
“chance favors the prepared mind”
What is the purpose of an experiment
an observation of a natural phenomena carried out in a controlled manor so that results can be duplicated and rational conclusions can be made
What is a theory
A tested explanation of a basic natural phenomenon, we cannot prove a theory to be true
What is a law
A concise statement or mathmatical equation about a fundamental relationship or occurrence in nature
What is the Phlogiston Theory, and an example of it
A theory in the 18th century that said when combustible bodies burn they release “phlogiston”
ex) wood=>burn it=>ash+phlogiston
(thought this because ash weighs less then the wood)
Law of Conservation of Mass
The total mass remains constant during a chemical reaction, and mass is neither created nor destroyed
Characteristics of solid matter
- incompressible
- fixed shape
- fixed volume
Characteristics of liquid matter
- incompressible fluid
- no fixed shape
- fixed volume
Characteristics of gas matter
- compressible
- no fixed shape
- no fixed volume
What is a physical change
- A change in the form of matter (not chemical identity)
- reversible
- no new compounds
What is a chemical change
- transformation of one (or more kinds) of matter into a new kind of matter (or several new kinds of matter)
- new compounds are formed
What is a physical property and an example of it
a characteristic that can be observed for a material without changing its chemical identity
ex) state of matter or color
What is a chemical property and an example of it
a characteristic of matter involving chemical change
ex) acidity or reactivity
Can mixtures be seperated
mixtures can be seperated by physical methods into 2 or more substances
elements
A type of matter that is composed of atoms with the same atomic number (# of protons in the nuclei)
compounds
a substance that contains 2 or more elements
What is the Law of Definite Proportions and who is responsible for it
In a pure compound, the elements are always present in a definite proportion or % by mass (no matter what method of preparation) (Proust)
Law of Constant Composition
a given chemical compound alwas contains its component elements in a fixed ratio