IntrototheChemistry化学基础知识英文简介PPT

Structural formula shows the arrangement of the
atoms in a single molecule
Molecules - example
Glucose Sugar
C6H12O6 Chemical formula
H H C OH
CO
H
H
C OH
OH
C
H HC
• always contain C & H and usually O, N, sometimes S&P
• originate in organisms
• generally complex molecules
Examples of Inorganic Compounds
H + O = H2O = Water H + Cl = HCl = Hydrochloric Acid Na + Cl = NaCl = Common Table Salt
Indefinite Volume
(can expand and be compressed)
Elements one of the 100+ pure substances
that make up everything in the universe
All they are displayed in the Periodic Table of the Elements
Liquid
Indefinite Shape
(takes the shape of the container)
Definite Volume (can not be compressed)
Gas
Indefinite Shape
(takes the shape of the container)
the way the elements are shown in the periodic table
6
C
12.011
Atomic # = # of p+ and # of eCarbon has 6 p+ and 6 e-
Atomic Mass minus Atomic # = # of n0 Carbon has 6 n0
Chemical Formula: C6H6 Chemical Formula: C4H10
Structural Formula:
Indicates the type of bonds and which is the order the atoms are linked inside the molecule
Protons p+ - positive charge, in nucleus Neutrons n0 – no charge, in nucleus
Electrons - e- negative charge, orbiting nucleus
Drawing an Atom of Carbon:
In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules
e-
e-
Compounds
Compounds : 2 or more elements
chemically combined to form a new
substance with
new prope way a chemical substance looks and behaves
To form:
1 compound More than one compound
Chemical equations- Reactions
Chemical equations describe chemical reactions
They show:
Reactants Products Quantities
Functional groups
Alcohol
Amina
Functional groups
Éter
Amida
Carboxylic acid
O=C=O Anhydride
Functional groups
Aldehyde
Halide
ketone
Compounds
Compounds: are made of 2 or more different atoms combined to form
Molecules
H+O
H2O =
O
H
H
Chemical formula lists the number of different atoms
in a single molecule
Examples of Elements
Note: The first letter has to be in Capital letter and the second in lower case
C = Carbon
Na = Sodium
O = Oxygen
Ca = Calcium
H = Hydrogen
The rest of reactants that are present in higher amount than the neccesary to react with the limiting reactant are called reactants in excess.
Functional groups
Chemical Reaction Process where two or more substances (reactants) are converted
in other substances (products)
Possible reactants:
2 elements 1 element and 1 compound 2 compounds
OH C
H OH
Structural formula
Compounds
Inorganic Compounds
or
Organic
Compounds
• usually don’t contain Carbon
• generally come from the earth
• generally simple molecules
Molecules
Mol
Is the basic unit in the International System of Units, and it allows measure the substance´s quantity
Molar Mass: [g/mol]
If it´s referred to atom, it represents the mass of a mol, expressed in grams
K = Potassium
N = Nitrogen
I = Iodine
S = Sulfur
Cl = Chlorine
P = Phosphorus
Atom: the smallest particle making up elements
Sub-atomic Particles: particles making up atoms
Stoichiometry is the Quantitative study of reactants and products involved in a chemical reaction
Limiting reactant
+ +
+
The reactant that is used totally in a chemical reaction is called: Limiting reactant
Cation A cation is a ion with positive electric charge. This means with a “default”
of electrons
Salts are mainly constituted by anions and cations
Chemical equations- Reactions
Examples of Organic Compounds
(according to the arragement of their atoms)
C, H + O
Carbohydrates = Sugars, starches & cellulose
Lipids = Fats & Oils
Examples of Organic Compounds
(according to the arragement of their atoms)
C, H, O, N, & sometimes P + S
Proteins
C, H, O, N, + P
Nucleic Acids – DNA & RNA
Molecules
molecules are formed for specific combinations of atoms. NEUTRAL charge
If it´s referred to molecules, Molar mass is the sum of the molar mass of all the atoms that constitute the molecule
Chemical Formulas
The Chemical Formula indicates the number of atoms of each type that constitute the molecules
HHHH HCCCCH
HHHH
Ions
Ion A ion is an atom or molecule with positive or negative electric charge. This
is due to the excess or default of electrons.
Anion An anion is a ion that has negative charge, has “excess” of electrons
Chemistry: Introduction
Matter
Matter = any material substance with Mass & Volume
Matter comes in 3 phases
Solid
Gas
Liquid
Solid
Definite Shape
Definite Volume
Drawing an Atom of Carbon
e-
Protons p+ - positive charge, in nucleus
e-
Neutrons n0 – no charge, in nucleus
e-
6 p+
e-
6 n0
Electrons - e- negative charge, orbiting nucleus