Sanitary Chemistry

Chemistry

A branch of physical science that studies composition, structure, properties and change of matter

Environmental Chemistry

Study of chemical processes occurring in the environment which are impacted by human activities

The Black Art

Chemia

Green Chemistry

It is design of chemical products abd processes that reduce or eliminate the generation of hazardous substances

Green Chemistry

Also called sustainable chemistry which seeks to reduce potential pollution at its source

Thales

Known as the first Chemist

Democritus

Gave the first idea of the composition of matter

Empedocles

Gave the first idea of elements, classified as earth, fire, air and water

Geber

Invented infiltration, sublimation, crystallization, distillation and was the first to prepare nitric and sulfuric acid

Matter

Anything that has volume and has mass

Physical Change

A change not involving a change in the substance's chemical identity

Element

Cannot be broken down into simpler substances

Compound

Can be broken down into two or more elements

Mixture

Can be separated by physical means

Atom

Greek word "atomos"

Electrons

Negatively charged particles

Protons

Positively charged particles

Neutrons

Electrically neutral

Atomic number

Number of protons in the nucleus

Mass number

The total number of protons and neutrons in the nucleus

Charge

The number of electrons added or removed in a neutral atom

Group 1A

Alkali metals except H

Group 2A

Alkaline Earth metals

Group 3A

Boron Family

Group 4A

Carbon Family

Group 5A

Nitrogen Family

Group 6A

Oxygen Family (Chalcogens)

Group 7A

Halogens

Group 0 or Group 8A

Noble gases

Metals

Shiny solids at room temperature the conduct heat and electricity well and are malleable and ductile

Nonmetals

Generally gases or dull, bruttle solids at room temp and conduct heat and electricity poorly

Metalloids

Semi metals

Atomic size

The size of the atoms become bigger as the number of shells increases

Ionization energy

The amount of energy required to remove an electron from an atom

Electron Affinity

The amount of energy released wgen an electron is added to an atom

Electronegativity

This is defined as the tendency of that atom to attract electrons towards itself

Law of conservation of mass

The total mass of substances does not change during a chemical reaction

Law of definite composition

No matter what it's source, a particular compound is composed of the same elements in the same parts by mass

Law of multiple proportions

If elements A and B react to form two compounds, the different masses of B that combine with a fixed mass of A can be expressed as a ratio of small whole numbers

Chemical Formula

A notation of atomic symbols and numerical subscripts that shows the type and number of each atom in a molecule or formula unit of a substance.

Empirical Formula

Shows the relative number of atoms of each element in the compound

Molecular Formula

Shows the number of atoms and bonds between them

Formula weights

The molecular weight in grams of any particular compounds

Mole

The SI unit for amount of substance

Precipitation reaction

Refers to the formation of an insoluble salt when two solutions containing soluble salts are combined

Oxidation - reduction reaction

Type.of chemical reaction that involves a transfer of electrons between two species

Molarity

The number of moles of solute per liter of solution

Molality

The number of moles of solute per kilogram of solvent

Mole fraction

Mole of solute per total mole of solution

Normality

Reported as equivalents/L

Turbidity

Water that contain suspended mattet that interfere with passage of light through the water by scaterring or absorbing rays or in which visual depth is restricted

Aesthetics

Turbidity in water is associated by the consumers to contamination and health hazard

Filterability

Turbidity shortens filter runs and increases water purification costs

Disinfection

Pathogenic microorganisms may be encased in the particles and protected form disinfectants

Clear lake

25 JTU

Noticeable to average water consumer

5 JTU

Muddy Water

Over 100 JTU

JTU

Jackson Turbidity Unit

NTU

Nephelometric Turbidity Unit

pH

Measures acidity and alkalinity condition of a solution

Indicator

That exhibit significant color changes in particular range involved

Phenolphthalein's pH

8.3

Methyl Orange's pH

3.7

pH meters

Using glass electrodes which develop a potential related to tge hydrogen-ion activity w/o interference from most other ions

Litmus paper

One of the oldest forms of pH indicator

Acidic conditions

Blue litmus paper turns red

Basic conditions

Red litmus paper turns blue

Neutral litmus paper

Purple

Alkalinity

A measurement of capacity to neutralize acids

Hardness

Caused by divalent or multivalent cations or positively charged metallic ions

Classification of hardness - SOFT

0-75 ppm

Classification of hardness- MODERATELY HARD

75-150ppm

Charles' Law

150-300ppm

Classification of hardness- VERY HARD

Greater than 300ppm

Boyle's Law

At constant temp the volume occupied by a fixed amount of gas is inversely proportional to the applied pressure

Charles' Law

At constant pressure, the volume of a fixed amount of gas is directly proportional to its absolute temp