Chapter 2 (Matter) Flashcards
Mixtures
Composed of more than one substance and can be physically separated into its component substances.
Two types:
1. Homogenous mixtures
2. Heterogenous mixtures
Matter
Any substance that has a mass and occupies volume.
Can be divided into two classes:
1. Mixtures
2. Pure substance
Pure substance
Composed of one substance and CANT be physically separated. Has constant composition Two types: 1. Compounds 2. Elements
Compounds
Can be chemically separated into individual elements
water -h2o- separated into hydrogen and oxygen
Elements
A single atom
Cannot be broken down any further by chemical reactions and still retain same properties
(Gold, iron, oxygen)
Homogenous mixtures
Ex: apple juice
Uniform properties through out.
Also called solutions; evenly mixed
(Ex: salt dissolved into water)
Heterogenous mixtures
Ex: blood
NO uniform properties; visible
Ex: sand & water
Atom
Basic building block of all matter
Molecule
Smallest particle of a compound
Law of constant composition
The ration by mass of the elements in a compound is always the same.
-Compounds have a constant composition, mixtures do NOT (can be used to differentiate b/w the two)
Colloid
A heterogenous mixture whose particle size in intermediate between those of a solution and a suspension
Law of definite proportions
States that compounds always contain the same elements in a constant proportion by mass.
Chemical formula
Sulfuric –> H2SO4
Number of types of atoms in a compound
Dispersion Medium
The material in which the particles are distributed
Tyndall effect
Phenomenon in which the dispersed particles of a colloid cannot be separated by filteration but scattered by light
– chattering of visible light by colloidal particles
Emulsions
A colloidal dispersion of a liquid or solid
Physical property
Observed without changing the identity of a substance
Chemical property
Observed when a substance is changed into a new substance
Physical changes
Changes that do NOT alter the identity of a substance.
; (separation of mixtures, physical deformation like cutting, denting, & stretching)
; (changes of state)
Chemical changes
One substance turned into another.
Ex: burning paper
Solid
Has a definite shape and volume
Liquid
Definite volume, but indefinite shape
Gas
No definite shape, no definite volume
Distillation
For two or more pure liquids
Vaporized, condensed, isolated
Takes advantage of differences in boiling points
Evaporation
Removes a liquid from a solution to leave a solid material
Filtration
Separates solids of different sizes
Separates pure substances
Calorimeter
- device used to measure changes in thermal energy or heat transfer
- It measures calories
Calorie
the amount of energy required to raise one gram of water by one degree Celsius.
Calorimetry
A way to measure the energy change of a reaction or the energy contained in matter
Another example of a physical change
Ice melting and then water boiling
Silicon is a
Metalloid
Liquid state
No definite shape, but definite volume
The greater the kinetic energy the
Higher the temperature of particles
A heterogenous mixture example
Chocolate chop cookie
What is he method used to obtain pure water from contaminated water?
Distillation
A nonmetal is usually
Brittle
The vertical columns on period tables are
Groups
Example of homogenous mixture
Clear air
Metalloids are often
Semiconductors of electricity
What happens to energy in a substance when it changes state ?
Neither increased nor destroyed, but changes form
Method used to separate water form sand?
Filtration
Chemical defined as
Any substance that has a definite composition
A substance is metal if it’s
A good conductor of heat and electricity
Chemical change
New identity
Zinc is a
Metal
When there are particles that settle in a mixture it’s called
Suspension
Another example of a physical change
Ice melting and then water boiling
Silicon is a
Metalloid
Liquid state
No definite shape, but definite volume
The greater the kinetic energy the
Higher the temperature of particles
A heterogenous mixture example
Chocolate chop cookie
What is he method used to obtain pure water from contaminated water?
Distillation
A nonmetal is usually
Brittle
The vertical columns on period tables are
Groups
Example of homogenous mixture
Clear air
Metalloids are often
Semiconductors of electricity
What happens to energy in a substance when it changes state ?
Neither increased nor destroyed, but changes form
Method used to separate water form sand?
Filtration
Chemical defined as
Any substance that has a definite composition
A substance is metal if it’s
A good conductor of heat and electricity
Chemical change
New identity
Zinc is a
Metal
When there are particles that settle in a mixture it’s called
Suspension
Kinetic energy
Any form of energy that cannot be stored
Thermal energy
Total mechanical energy of an objects or a materials particles
Extensive property
Temperature
Average mechanical energy of the particles that compose a material
Kinetic molecular theory
Explains what happened to matter when the kinetic energy of particles changes
Key points:
1. All matter is made up of tiny particles
2. There is empty space between particles
3. Particles are always moving
4. Particles move because of energy
Evaporation (vaporization)
Condensation
Sublimation
Deposition
Liquid to gas
Gas to liquid
Solid to gas
Gas to solid
Vapor
Gas formed by a substance that boils above room temperature
Volatile substances
Substances that readily evaporate or evaporate at high rates
Heat of fusion
The amount of heat required to melt a specific amount of a substance at its melting point
Potential energy
Stored energy
Heat of vaporization
The amount of heat required to evaporate a specified amount of a substance at its boiling point
Heat of formation
The heat released when a substance is formed from its elements (J/g)
Heat of combustion
The heat released when a specified amount of a substance undergoes complete combustion with oxygen
Alloys
Mixtures containing metals
Binary compound
Composed of only two elements
Ion & ionic bond
Charged atom & the bond attraction b/w oppositely charged ions
Molecular compound
Any compound with a nonmetal (NM+NM) except for any containing ammonia (ionic)
Covalent bond
A shared pair of valence electrons that holds two atoms together
Acid
A special type of molecular compound ..
Base
A hydroxide
Salt
An ionic compound other than a hydroxide
Two types of Ionic compounds
Salts and bases
Two types of Homogeneous mixtures
Solutions and colloids
Physical separations
Those not involving a chemical reaction Centrifugation Chromatography Distillation Filtration
Non-mechanical physical separation
Includes techniques that use heat, electricity, magnetism, dissolving etc
Mechanical means of separation
Gravity, contact forces, or motion to sort the components of a mixture
Sediment
To fall or sink to the bottom of a liquid
Matter that has called or sunk to the bottom of a liquid
Is there such thing as a charged compound?
No, all compounds are neutral
Multivalvent ions
Ions that have more than one valence shell electron. Many of the transitions metals do.
Ex) fe3+ fe2+
Polyatomic ion
A charged group of covalently bonded atoms (like a molecule, except with a charge)
To determine the names of ionic compounds
- Write the names of the possible ions
2. Write the formulas to see which one is correct
You only use prefixes when you are naming which type of compound?
Binary Molecular compounds (two nonmetals), never ionic
Ex) xenon tetra fluoride –> XeFe4
The names if all binary compounds have a suffix of what?
Do we use the prefix “mono” for the first element?
-ide
No, “Mono” is understood for the first element, so it is not needed.
Hydrates
a compound (salts), typically a crystalline one, in which water molecules are chemically bound to another compound or an element.
Gently warming a hydrated salt will usually…
Remove the water from the crystal
Anhydrous
Refers to the form of a salt without water
Some salts are hygroscopic which means..
They can absorb water from the air to form hydrates
How to determine the formula of a hydrate from its name
- Write the sum hold of the ions named
- Combine the ions to form the equation
- Tack on the appropriate number of water molecules to compensate the formala
Ex) copper(II) sulphate heptahydrate
Cu2+ SO4 2- —> CuSO4
Heptahydrate—> 7H2O
So: CuSo4 * 7H2O
To name an acid without an oxygen atom
“Hydro”(proceeds the name of the anion) & “-ic” (replaces -ide)
Ex) HF (hydrogen fluoride) = hydroflouric acid
HCN (hydrogen cyanide) = hydrocyanic acid
To name an acid with an oxygen atom
“-ic” replaces “-ate” ex) hydrogen sulfate (h2so4) is sulfuric acid
“-ous” replaces “-ite” ex) hydrogen sulfite (h2so3) is sulfurous acid
