CHEMISTRY

Chemistry is the study of the composition of substances and the changes that substances undergo.

Branches of Chemistry

Organic Chemistry is the chemistry of Carbon (except pure C,

CO2, CO, CO32-)

Inorganic Chemistryis the chemistry of other elementsAnalytical ChemistryInvolves chemical analysis bothqualitative and quantitative.

Biochemistryis chemistry of biological systemsPhysical Chemistryis the physics end of chemistry

MATTER

Matter is anything that takes up space and has mass.

Classification of Matter

E L E M E N T(ex. iron , su lfu r,

ca rb on ,h yd rog en

C O M P O U N D(ex. iron ,su lfid e

wa ter

S U B S TA N C ED efin ite com p os it ion

H O M O G E N E O U SM IX TU R E

U n ifo rm th rou g h ou t a lsoca lled a so lu t ion (a ir)

H E TE R O G E N E O U SM IX TU R E

N on u n ifo rm ;d is t in c t p h ases(sou p , con c re te )

M IX TU R EV ariab le c om p os it ion

M atte r

States of MatterSolids have a definite shape and volume.

Liquids have a fixed volume and take the shape of the container.Gases take both the shape and the volume of

its container.

Gas vs Vapour

A gas is asubstance that is normally gaseous at

room temperature. For exampleoxygen (O2), nitrogen (N2), Helium (He).

A vapour is a substance in the gaseous state and is

generally a liquid or solid at room temperature. For example

water vapour in the air

PHYSICAL PROPERTY

A physical property is a quality or condition of a substance that can

be observed or measured without changing the substance’s composition.Examples includecolour, solubility, mass, odour, hardness,

density, electrical conductivity, melting point, and boiling point.

Physical Properties of Some Common Substances

Gold (Au)solid at room T, yellow, lustrous, soft, ductile,

malleable, excellent electrical conductorMercury (Hg)liquid at room T, odourless, very dense,

excellent electrical conductorOxygen (O2)gas at room T, odourless

Physical Change

Altering a substance without changing its chemical composition.Examples include:melting/freezing, boiling, cutting, grinding, bending, or change in temperature

Chemical Properties

Properties of a substance which can be observed when the substance undergoes a change in chemical composition

Examples include reactivity with oxygen—for exampleflammability & rusting;reactivity with water; reactivity with acids, etc.

Chemical Changeis a change that alters the composition of

matter. For examplerusting, baking, cooking—any chemical

reaction that produces a new compound.Combustion of methane, CH4, CH4(g) + 2 O2(g) CO2(g) + 2 H2O(g)

Reduction of CuOCuO(s) + CH4(g) Cu(s) + CO2(g) +H2O(g)