Chemistry Term 1

Chemistry

- The study of matter
- the chemical composition and properties of a substance or object

Matter

- Anything that has mass/volume.
- Anything that takes up space.

Branches of Chemistry

- Inorganic chemistry - Properties, structures, inorganic compositions.
- Organic chemistry - Properties, structures, organic compositions.
- Analytical chemistry - Calculations and specifications of matter.
- Physical chemistry - Different processes in chemistry.
- Mechanisms, rate, energy, transfer.
- Biochemistry - Animals, plants, etc. (More on biology).

Composition

identity and number of the chemical elements that make up any particular compound

Pure substance

Matter with a definite composition
- Melts and Boil at a definite temperature
Ex: H2o

Effects of impurities

affects the value of the melting or boiling point of a substance

Elements

the simplest form of matter that cannot be broken down.

Compounds

chemically bounded group (Two or more) of atoms or elements.

Mixture

- varying composition
- not chemically combined
- can be separated using different techniques
- keep their identity
Ex: Milo in water - can taste still taste milo

Physical change

A change in shape or appearance
Ex: Crumpling paper

Chemical change

Producing a new substance
Ex: Burning paper -> ashes

Metals

Ex: Iron, gold

Non-metals

Ex: Carbon

Metalloids

Ex: Silicon

Diatomic element

Two atoms combined when you see them in nature.
Ex: Hydrogen H2, Nitrogen N2, Oxygen O2

Democritus

- first to hypothesize that matter could be divided.
- Atoms are indivisible and indestructible particles that make up matter.
- Atoms of the same elements are exactly alike and the same is for the opposite.
- Compounds are formed by the joining of atoms of two or more elements.

3 states of matter

- Solid
- Liquid
- Gas

room temperature

25°C

The difference between all three states

particle model

What are substances made up of?

particles

Particles that move around posses what?

Kinetic Energy

How does kinetic energy increases?

Increases with temperature

Particles in a solid - animation

move by vibrations because of low kinetic energy and strong attraction.

Particles in a liquid - animation

Particles in a liquid move by sliding into another because of moderate kinetic energy and moderate attraction.

Particles in a gas - animation

Particles in a gas move by spreading apart because of high kinetic energy and almost no attraction.

Colloids

Mixtures of two or more substances can lead to an overlap between the three states

What happens when particles flow?

mix with other substances already present.

Properties of solid

- Fixed volume
- High density
- Not compressible
- Has definite shape—lattice
- Does not flow

Properties of liquid

- Fixed volume
- Moderate density
- Not compressible
- No definite shape
- Flows easily

Properties of gas

- No fixed volume
- Low density
- No definite shape
- Flows easily
- Compressible
- Can cause pressure

Gas to Liquid

Condensation

Liquid to gas

Evaporation

Solid to gas

Sublimation

Gas to solid

Deposition

Solid to liquid

Melting

Liquid to solid

Freezing

volatility

the property of how easily a liquid evaporates

Brownian Motion

- Random motion
- Higher concentration to lower concentration

placement of time in a heating and cooling curve

Bottom

↗

increase

↙

decrease

—

- static
- constant
The melting and boiling points can have a constant temperature and in that constant temperature, kinetic energy helps the attraction start breaking down.

Diffusion

movement in particles that allows them to spread out & mix with other particles

Rate of diffusion depends on?

the mass
- Big mass = rate of diffusion slower
- Small mass = rate of diffusion faster

Solution

formed when a substance (solute) dissolves into another substance (solvent)

solute

the dissolved matter in a solution; the component of a solution that changes its state

solvent

a liquid substance capable of dissolving other substances

Homogeneous

- single phase
- evenly distributed particles - no lumps
- Ex: juice

heterogeneous

- 2 or more phase
- not uniform distribution
- Ex: cereal & milk

dissolving

separate and spread evenly

soluble

will dissolve

insoluble

will not dissolve

aqueous solution

a solution in water
universal solution

concentration

amount of solute dissolved in solvent

qualitative

Dilute & Concentrated

Dilute

- less solute
- lessen the strength or flavor of a solution or mixture

Concentrated

- more solute
- intensely focused

quantitative

Solubility, Saturated, unsaturated, supersaturated

solubility

how much of solute can dissolve in solvent in a particular temperature

saturated

maximum solute dissolved

unsaturated

not saturated; capable of dissolving more of a substance at a given temperature

supersaturated

- more than max solute is dissolved
- can only be made with heat

How to speed up dissolving

- Mixing - stirring or shaking
- Heating - causes particles to move more quickly and separate (can't be applied to gases)
- Crushing - increase the amount of contact between solute & solvent

Gasoline

solution that is not a aqueous
doesn't have water

Brass, Steel

solid solution

suspension

a moisture where particles are mixed in a solvent but do not dissolve because they are large
ex: Blood, inside of a Snow globe

colloid

Mixtures of two or more substances can lead to an overlap between the three states.
- particles are smaller than in suspension
Ex: Slime, Ice