Chemistry Prelim

Properties of Alloy: -Iron and carbon (elements) -Hard -High tensile strength

Properties of Alloy: -Copper and zinc (elements) -Lustrous gold appearance -Hard but easily machined

Properties of Alloy: -Tin and lead -Low melting point -Adheres firmly to other metals when molten

Process: To turn a metal oxide into pure metal involves the removal of the oxygen from the metal oxide

Chemical decomposition produced by passing an electric current through a liquid or solution containing ions.

Is a mixture of more than one metal to produce a material with specific physical and chemical properties

All matter is made of continuously moving particles

Matter can be changed from one form into another, mixtures can be separate or made, and pure substances can be decomposed but the total mass remains constant.

An electron that has left its outer shell

All atoms of the same element have the same number of protons in the nucleus, however they do not necessarily have the same mass. These atoms differ in the numver of neutrons and therefore mass number

A way of representing the valence electron configuration of an atom and show how valence electrons are arranged in compounds

The amount of energy required to remove the most losely bound electron from an atom or ion in the gaseous state

Properties of bond:

• very high M.P and B.P

• Non-conductors -Extremely hard

A substance dissolved in another substance, usually the component of solution present in the lesser amount

A substance in which another substance is dissolved, forming a solution

A homogeneous mixture of two or more substances, which may be solids, liquids, gases, or a combination of these

Mass/ volume

Are formed when dead and decaying material burns before complete decomposition

Often formed in swamps and mangroves

Mostly formed from the remains of buried aquatic organisms (e.g. plankton) broken down by anaerobic bacteria

Mostly the remains of buried aquatic organisms

A substance that speeds up a chemical reaction, but is not consumed by the reaction hence a catalyst can be recovered chemically unchanged at the end of the reaction

Occurs between hydrogen atoms and unshared pairs of electrons of N, O or F atoms- resulting in an unequal sharing of electrons leading to a partial positive charge on the H-atoms

Single bond

Double bond

Triple bond

It works by evaporating tone of the liquid from the solution, it is then cooled and condensed into a separate container and the other liquid is left behind

The resistance of a liquid to flow- it increases with stronger intermolecular forces and decreases with higher temperatures

A solution in which the maximum amount of a solvent has been dissolved. Once this is achieved an equilibrium is established

Properties of a type of molecule:

• Low B.P

• Very volatile

• Flows easily

• Ignites easily

Properties of a type of molecule:

• High B.P

• Not very volatile

• Does not flow easily

• Does not ignite easily

Compounds with the same molecular formula but different structural arrangements are known as structural isomers

When a charge on one object distorts the distribution of charge on a nearby object, producing an induction of charge and a force of attraction between the two objects e.g. rubbing a balloon on your skirt causes static in your hair

The result of an ion distorting the electron density of a non-polar molecule

The relative tendency of a charge distribution to be distorted from its normal shape by an external field

The weakest kind of intermolecular attraction and occurs between molecules- they are caused by the motion of electrions

Same pattern & similar formula- it is like the same molecule that is getting bigger

loss of electrons to become a positive ion

Theory for the atom: o The nucleus is the central part of the atom that contains protons and neutrons o The electrons move through a relatively large space outside the nucleus in shells o The electrons are kept moving around the nucleus by electrostatic charges between the positively charged nucleus and negatively charged electrons

-Increase down a group as each successive element has one more electron shell- due to additional energy levels -Decrease left to right as more electronegative, the charge in the nucleus increase so the electrostatic force between the nucleus and the outer electrons is stronger holding it closer to the nucleus

-Increases across a period as atomic radius decreases -Decreases down a group as atomic radius increases

-Increases from left to right as more electronegative -Decreases down a group as less electronegative (electrons further away from nucleus)

Developed a table of the elements based on increasing atomic weight

"When measured at constant temperature and pressure, the volumes of gases taking part in a chemical reaction show simple whole number ratios to one another."- theory

"When measured at the same temperature and pressure, equal volumes of gases contain the same number of molecules." - Law

A natural substance occurring in the Earth's crust, which is a compound (hence pure) with a definite composition and crystalline structure e.g. Al2O3

A compound or mixture of compounds (or minerals) from which it is economic to extract a substance such as a metal e.g. bauxite (contains mineral Al2O3)

A molecule in which there is an uneven charge distribution

Occurs between oppositely charged ends of permanent polar

(attraction between unlike molecules) pulls the molecules inward and closer together, making the liquid surface behave like an elastic skin under tension.

(attractive forces between like molecules) cause the droplet to assume a spherical like shape to minimise the surface area.

Is a measure of the energy needed to increase the surface area of a liquid by a unit amount.

An insoluble ionic compound formed as a solid in solution from solutions of two soluble ionic compounds

Occurs when the force of attraction between the two ions is stronger than the electrostatic attraction between the water molecules and the ions

A dynamic situation in a closed system, where there is continual interchange between reactants and products in a reaction at the atomic level but with no observable change at the macroscopic level

The amount of a given substance dissolved in a specified amount of solution

The heat needed to raise the temperature of 1 unit mass of a substance by 1 Kelvin Degree

A chemical dissolves in water and heat is released causing a temperature rise

The action or process of dissolving

A chemical dissolves in water and heat is absorbed causing a drop in temperature

The discharge into a river or lake of quantities of hot water that are large enough to increase significantly the temperature of the water body

Metal + Oxygen --> metal oxide

Fuel + oxygen ---> carbon dioxide + water

Glucose + oxygen ---> carbon dioxide + water

Soluble salt + soluble salt ---> insoluble salt + soluble salt

Acid + Base ---> salt + water

Is used to determine the mass and/ or percentage of different components in a sample (usually a mixture)

the process of removing dissolved salts and minerals from seawater or brackish water. It is also called desalting or by its shortened name, desa

Can be used for electrical wires because they are generally ductile and good conductors of electricity

The particles have more space between them and have translational and vibrational motion (vibrate slightly and fill up what its contained in)

The particles have a lot of energy, they don't interact with each other as much and have rapid translational motion

The particles are orderly arranged and closely packed- because the particles are closely packed together in solids than in liquids, solids have greater densities (with the exception of water and ice)

protons + neutrons

Protons= electrons

A charged particle formed when an atom gains or loses one or more electrons

Are formed between two of more atoms sharing electrons

Do not involve the production of new substances, and are reversible

form one or more new chemical substances

Occurs between metals and involves the electrostatic attraction between delocalised electrons and the metal cations, which hold the 3D lattice together.

Involves the transfer of electrons from one atom to another. The bonding consists of electrostatic attraction between the positive and negative ions formed by this transfer of electrons, which hold the 3D lattice together.

Is the simplest form of a compound and represents the simplest whole number ratio of atoms/ions in the crystal.

Properties:

• High melting and boiling points. Hard. Crystalline

• Good electrical conductors when molten

• Good electrical conductors when in solution

• Poor electrical conductors when in solid.

Properties:

• Poor conductors of electricity in all states

• Not hard

Properties:

• Poor conductors electricity in all states

• Hardness

Properties:

• Good conductor of electricity

• High melting and boiling points. Hard

• Good conductor of heat

• Malleable and ductile

• Shiny lustre

When they are mixed, they do not form a homogeneous liquid, but instead stay as drops of one liquid dispersed through the other liquid

Are forms of the one element (in the same physical state) that have distinctly different physical properties

The ease with which it can be converted to a vapour; it decreases as boiling point increases

Is the minimum amount of energy reactant molecules must possess in order to form products (kJ/mol), on an energy profile diagram, it is the space between the reactants and the peak