1.1 GENERAL CHEMISTRY (Part 1)

Chemistry

The study of matter, its properties, and the changes it undergoes

Inorganic Pharmaceutical Chemistry

• Study of inorganic substances used as: 

  • Medicines 

  • Preparation of pharmaceutical products

Matter

Anything that occupies space and has mass

Substance

A form of matter that has a definite composition and distinct properties

Substance

• example

• water

• ammonia

• sucrose

• gold

• oxygen

Atom

Basic unit of a chemical element

THREE STATES OF MATTER

• Can be interconverted without changing the composition of the substance 

• Can change states by heating & cooling

Three states of matter include:

• solids

• liquids

• gases

Solids

• Rigidity and definite form/ shape 

• Resist flow

Liquids

No definite shape & flow (takes the shape of the container)

Gases

• No definite shape, can diffuse/ spread/ scatter and fill the container whenever they are placed

• Particles move independently of one another

MIXTURE

A mixture is a combination of two or more substances in which the substances retain their distinct identities 

Homogenous mixture

• Composition of the mixture is the same throughout 

• One-phase solution

Homogenous mixture

• example

• softdrink

• milk

• solder/fuse

Heterogenous mixture

• Composition is not uniform throughout 

• 2 or more phases

Heterogenous mixture

• example

• cement

• iron filings in sand

3 CATEGORIES OF ELEMENTS

• metals

• non-metals

• metalloids

element

a substance that cannot be separated into simpler substances chemical means.

Metals

• Lustrous, good conductors of heat & electricity 

• Loses electron/s and forms cation

Non-metals

• Non-lustrous, non-conductors of heat & electricity 

• Gains electron/s and forms anion

Metalloids

Exhibits both properties of metals & non-metals

PERIODIC TABLE

• is designed by

Dmitri Mendeleev

Elements are arranged according to

their increasing atomic number

Group (in the periodic table) is based on _

their chemical properties/ valence electrons

Valence Electrons

• Electrons available for bonding 

• Electrons found in the outermost shell of the atom

Octet Rule

Atoms lose/gain electrons to achieve a stable electron configuration like the noble gases

Representative Elements

Found in the outermost shell and correspond to their group number

Transition Elements

Outer electrons and some electron from the inner orbitals

SPECIAL NAMES

• I-A: Alkali

• II-A: Alkali Earth

• VII-A: Halogens

• VIII-A: Noble Gases

NAMED AFTER THE FIRST ELEMENT OF THE GROUP

III-A: Boron Group

IV-A: Carbon Group / Crystallogens

V-A: Nitrogen Group / Pnictogens

VI-A: Oxygen Group / Chalcogens

4 PERIODIC CLASSIFICATION OF ELEMENTS

• Representative element (A subgroups)

• Transition Element (B subgroups)

• Inner Transition (Lanthanide & Actinide)

• Noble Gases/ Inert Gases/ Group 0

Representative element (A subgroups)

Last electron in outer s or p orbital (s¹- p⁵)

Representative element (A subgroups)

• Group no. 

• Corresponds to valence electron 

• With regular variations on their properties 

Transition Element (B subgroups)

Incompletely filled d orbitals

Inner Transition (Lanthanide & Actinide)

• Incompletely filled f orbitals 

• 2 series of elements

Noble Gases/ Inert Gases/ Group 0

Filled s or p orbitals with 8 valence electrons (except He)

COMPOUND

• Compound of atoms of two or more elements chemically united in fixed proportions 

Compounds can only be separated in their pure components (elements) by _

chemical means 

Compound

• examples

• Water (H₂O) 

• Glucose (C₆H₁₂O₆)

• Ammonia (NH₃) 

General Types of compound

• molecular

• Ionic

Molecular compound

Form of individual molecules composed of atoms (non-metals)

Ionic compound

Formed from ions that are either cation (+) or anion (-) (metal & non-metal)

Molecule

Aggregate of two or more atoms in a definite arrangement held together by chemical bonds

Diatomic molecule

Contains only two atoms of the same element or different elements

Polyatomic molecule

Contains more than two atoms of the same element or different elements (molecular compound)

CHEMICAL FORMULA

• Symbols and ratios of atoms for the elements in a chemical compound

Different Types of Formula

Molecular Formula

Empirical Formula

Structural Formula

Electronic or Lewis Formula

Molecular Formula

• Formula based on actual molecule

• Gives the actual number of atoms of each element

Empirical Formula

• Based on formula units

• Gives the smallest whole number ratio

Structural Formula

• Arrangement of atoms in a molecule of a compound

• Compounds are connected with dashes.

Electronic or Lewis Formula

• Shows the distribution of electrons in the outermost shell of the atom

• Symbols of elements are written with dots around and these dots represent the number of electrons in the outermost shell of an atom.

MOLE (mol)

Amount of a substance that contains as many elementary entities (atoms, molecules, formula units or other particles) as there are atoms in exactly 12.00 grams of ¹²C

1 mol value

6.0221367x10²³ Avogadro's number (NA)

MOLAR MASS

• Mass of 1 mole of atoms in grams

Molar mass for any element

• = atomic mass (amu) = molar mass (grams) 

METHODS OF SEPARATING COMPOUNDS OF MIXTURE

• Decantation

• Distillation

• Evaporation

• Sorting

• Magnetic separation

• Filtration

• Centrifugation

• Fractional distillation

Components

Substances making up the mixture

Constituents

Substances making up the compounds

CHANGES MATTER UNDERGOES

• Physical change

• Chemical change / Chemical reaction / Simple reaction

• Nuclear Change

Physical change

Does not alter the composition or identity of the substance involved

Chemical change / Chemical reaction / Simple reaction

Alters the composition or identity of the substances involved

Nuclear Change

• New substance is formed (change in structure, properties, composition)

• Change in the identity of the nucleus of an atom; transmutation of an element to another element.

Nuclear Change

• example

• Disintegration of radioactive atoms in successive stages

GENERAL TYPES OF CHEMICAL CHANGES / CHEMICAL REACTIONS

Combination or Synthesis

Decomposition or Analysis

Displacement / Replacement / Substitution

Double Decomposition/ Double Displacement/ Metathesis/ Exchange

Chemical Change or Chemical Reaction

One or more elements or compounds react to form one or more different elements or compounds

2 Na + Cl₂ → 2NaCl

Combination or Synthesis

2 KClO₃ →  2 KCl+3O₂

Decomposition or Analysis

3K+FeI₃ →  3KI + Fe

Cl₂ + 2 NaBr → 2 NaCl + Br₂

Displacement / Replacement / Substitution

Li > K > Ba > Ca > Na > Mg > Al > Zn > Cr > Fe > Cd > Co > Ni > Sn > Pb > H > Cu > Hg > Ag > Pt > Au

Displacement / Replacement / Substitution

• activity series

F > Cl > Br > I

Displacement / Replacement / Substitution

• activity of halogens

NaCl + AgNO₃ → AgCl + NaNO₃

Double Decomposition/ Double Displacement/ Metathesis/ Exchange

REACTIONS IN AQUEOUS SOLUTIONS

• non-redox reactions

• redox reactions

Non-REDOX reactions

• No change in oxidation number 

Non-REDOX reactions

• examples

• Precipitation reactions

• Acid-base neutralization 

• Hydrolysis 

• Saponification 

• Fermentation

REDOX reactions

• Change in the electrical charge on the reacting particles;

• Change in oxidation number

• Simultaneous gain & loss of electrons

REDOX reactions

• examples

• Combination / synthesis 

• Decomposition / analysis 

• Displacement / replacement / substitution

Precipitation reactions

• aka Double Displacement / Metathesis / Exchange Reaction

Acid-base neutralization

Acid + base → salt + water

Hydrolysis

Water + salt → acid + base

Saponification

Alkali + fats/oil → soap + glycerol

Fermentation

Bacteria / microorganism + organic substance → alcohol

OXIDATION (LEORA)

• Substance loses electrons or increases in oxidation no. = substance loses electrons and thus increase in oxidation state

• (- → 0 → +)

• Donates electrons 

• Loses electrons (gain in oxidation number) 

• Said to be oxidized (substances which furnishes electrons)

REDUCTION (GEROA)

• Substances gains electrons or decrease in oxidation number = substance gains electrons and thus decrease in oxidation state 

• (+ → 0 → -)

• Accepts electrons readily 

• Gains electrons or take up electrons (loss in oxidation number) 

• Said to be reduced (substances receiving electrons)

ELECTROCHEMISTRY

• Area of chemistry that deals with interconversion of electrical energy & chemical energy 

COMMON TYPES OF ELECTROLYTIC CONDUCTANCE (ELECTROCHEMICAL PROCESSES)

Electrolytic cell

Voltaic or Galvanic cell

Electrolytic cell

• Electrical energy causes chemical reaction to take place - electrolysis

• EE→CE

Electrolytic cell

• EE→CE

• Non-spontaneous reaction; Transfer of electrons from cathode to anode.

• E⁰ < 0 (-)

Voltaic or Galvanic cell

• Chemical reaction produces energy 

• Change in oxidation number

• Simultaneous gain & loss of electrons

• CE→EE

Voltaic or Galvanic cell

• CE→EE

• Spontaneous; Transfer of electrons from anode to cathode.

• E⁰ < 0 (+)

Properties

• Qualities or characteristics of materials which enable us to identify them

Chemical Properties

• Chemical changes; involved In the alteration of composition

• Rusting or oxidation; chemical reactions

Physical Properties

• Physical changes; perceived by the senses/easily detected by the senses

Nuclear fission

• Heavy nucleus (mass no. >200) divides/splits to form smaller nuclei of intermediate mass & one or more neutrons 

Nuclear fission

• example

atomic bomb

Nuclear fusion

• Combining / union of small nuclei or 2 light atoms into larger ones/bigger molecule

Nuclear fusion

• example

nuclear bomb

DALTON’S ATOMIC THEORY

1. Elements are composed of extremely small particles called atoms

2. All atoms of a given element are identical, having the same size, mass, and chemical properties. The atoms of one element are different from the atoms of all other elements 

3. Compounds are composed of atoms of more than one element. The relative number of atoms of each element in a given compound is always the same 

4. Chemical reactions only involve the rearrangement of atoms. Atoms are not created or destroyed in chemical reactions 

DALTON’S ATOMIC THEORY

• Elements are composed of

• extremely small particles called atoms

DALTON’S ATOMIC THEORY

• All atoms of a given element are identical, having the same size, mass, and chemical properties.

• The atoms of one element are different from the atoms of all other elements 

DALTON’S ATOMIC THEORY

• Compounds are composed of atoms of more than one element.

• The relative number of atoms of each element in a given compound is always the same