CHEMISTRY #2

Etapa 1

MATTER

Everything is made up of matter, matter is anything that occupies space. Classified in mixtures and pure substances.

Chemistry is related to…

Mathematics, physics, biology, agriculture, engineering and medicine.

PURE SUBSTANCES

Kind of matter, has a fixed and constant composition, classified in elements and compounds.

ELEMENTS

Simplest form of matter. Impossible to decompose through chemical or physical processes, they are made up of atoms in their smallest particles.

COMPOUNDS

Combination of 2 or more elements, can be decomposed through chemical and physical processes. Example calcium carbonate.

MIXTURES

Union of 2 or more pure substances, physically but not chemically. Substance in highest proportion = dispersant phase and lowest proportion = dispersed phase.

HOMOGENEOUS MIXTURES

2 Or more substances, uniform appearance, named solutions and dissolutions.

HETEROGENEOUS MIXTURES

Not uniform appearance, two or more noticeable different physical phases.

SOLUTION

Homogeneous. Super small particles, do not settle at the bottom of container.

SUSPENSION

Heterogeneous. Opaque appearance, dispersed phase is solid and sinks to the bottom, ex. water and sand.

COLLOIDS

Heterogeneous. They are able to reflect on scatter light, ex. milk and mayonnaise.

DECANTATION

Separation of liquid from insoluble solid. Uses separation funnel.

FILTRATION

Separation of insoluble solid from a liquid. Liquid passes through a filter, filter retains solid.

CENTRIFUGATION

Used to separate an insoluble solid that is difficult to settle. Container is rotated at a high speed and solid settles to the bottom of container.

CRYSTALLIZATION

Happens after separation of solid dissolved in a solution, uses evaporation and turns solid into crystals.

SIMPLE DISTILLATION

Considers difference of boiling points, liquid with lower boiling point evaporates and is collected through a condenser and refrigerant.

FRACTIONAL DISTILLATION

Used when the substances all have different boiling points but they are close to each other. Same action as simple distillation is repeated until all components are separated.

Solids…

Have defined shape and volume. Particles remain in contact, have a fixed pattern and resist deformation.

Liquids…

Particles are in contact but move freely, adapts shape of container.

Gaseous…

Particles are very separated from each other and move quickly, have no defined shape or volume and adapts shape of container.

VOLUME

Measurement of space occupied by a body.

WEIGHT

Force exerted on a body by gravity.

INERTIA

The greater the mass, the greater the inertia.

IMPENETRABILITY

Property that prevents two bodies form occupying the same space at the same time.

POROSITY

Matter has empty spaces called pores.

PHYSICAL PROPERTIES

Characteristics that can be seen, measured and do not change the inner composition of the substance. Ex. state, smell, color, flavor, density, melting and boiling point, solubility, etc.

CHEMICAL PROPERTIES

Capacity of matter to create new substances. The chemical behavior needs to be identified in order to detect the changes in the inner structure. Ex. oxidation, combustion, and reduction.

DEPOSITION

Gas to solid.

SUBLIMATION

Solid to gas.

PHYSICAL CHANGES

Only its shape is affected, inner structure doesn’t change. Changes in state of aggregation of matter are an example, breaking, folding, freezing, dissolving. Possibility of transitioning into any of the three states.

PLASMA

Almost identical to gaseous, ionized gas that conducts electricity, much of the universe is made up of intergalactic plasma.

AGGREGATION STATES

Fusion, used in steel industry, Solidification, chocolate for desserts that is liquid to place in mold and frozen to me consumed.

ENDOTHERMIC CHANGES

If they absorb energy (when temperature increases) - fusion, evaporation and sublimation.

EXOTHERMIC CHANGES

If they release energy (when temperature decreases) - solidification, condensation and deposition.

CHEMICAL CHANGES

Transformation in matter that involves change in inner composition. Synonym of chemical reaction because 2 or more substances interact and make new substances when evolution of gas occurs, temperature changes, etc.

ENERGY

The ability of a body to perform work.

LAW OF CONSERVATION OF ENERGY

Energy is not created nor destroyed, it is only transformed.

LAW OF CONSERVATION OF MATTER

Energy and matter can transform each other, but the total of both in the universe does not increase or decrease.

CLEAN ENERGIES - alternative energies

They are obtained form inexhaustible sources such as wind, sun, water and movement. Ex=

• Solar

• Biomass - organic materials

• Tidal - tides or water currents

• Hydraulics - movement of water

• Geothermal - heat of earth’s interior

• Wind

NON-RENEWABLE ENERGIES

Fossil fuels of organic matter that was exposed to pressures and high temperatures for millions of years. Ex.=

• Oil

• Coal

• Natural Gas

• Biofuels

• Nuclear fuels