Unit 1/2 Exam Revision Flashcards
Groups
Column number indicated groups. Elements in the same column have the same number of electrons in the outer shell.
Periods
Row number indicates periods. Elements found in the same row have the same number of electron occupied shells.
Blocks
There are 4 different blocks in the periodic table. There is the S block, D block, P block and F block.
S block: Alkali and alkaline earth metals
D block: transition mental
P block: halogens, noble gases and metalloids
F block: lanthanides and actinides
Group 1
Alkali metals – form ionic compounds, very reactive metals with oxygen and water, low electronegativities, powerful reactants (lose electrons), relatively soft metal.
Group 2
Alkaline earth metals - form ionic compounds, reactive metals, low electronegativities, strong reactants.
Group 17
Halogens – reactive non-metals, form ionic and covalent compounds, high electronegativities, powerful oxidants (gain electrons)
Group 18
Noble gases – unreactive gases however a few compounds of krypton, xenon and radon have been made; outer shell contains 8 electrons except Helium.
Naming ionic compounds
When a non-metal gains one or more electrons, the name of the negative ion ends in –ide. When a metal atom loses one or more electrons, the name of the positive ion is the same as that of the metal.
- The first element (metal cation) in the formula is named in full
- The second element is named as an anion. The name is shortened and given an –ide suffix.
Intramolecular forces
Single covalent bond
Double covalent bond
Triple covalent bond
Intermolecular forces
Dispersion forces -> every bond contains it
Hydrogen bonds -> Only occurs when hydrogen binds to either: F, O or N
Dipole – dipole -> When a hydrogen bond does not occur
Naming covalent molecules
The first element remains the same but the second element gets the suffix of –ide. The first element gets a prefix unless there is only one molecule. The second element also gets a prefix: Mono = 1 Di = 2 Tri = 3 Tetra = 4 Penta = 5 Hexa = 6 Hepta = 7 Octa = 8 Nona = 9 Deca = 10
Isomers
Compounds with the same molecular formula by different structural formula
Conjugate Acid/base pairs
Differ by one proton.
H3O+/ H2O
H2PO4-/ HPO42-
Polyprotic acids
Have more than one proton to donate.
Amphiprotic acids
it can either donate or accept a proton.
Strong
The tendency to donate or accept a proton
Weak
The tendency to donate or accept a proton
Concentrated
Amount of original material added to water
Dilute
Amount of original material added to water
Spectator ions
any species that remains unchanged will be removed for the ionic equation.
Solubility rules
- all nitrates are soluble
- all chlorides, bromides and iodides are soluble, except those of silver, lead and mercury
- all sulfates are soluble, except those of barium, calcium and lead
- all carbonates are insoluble, except those of Group 1 metals.
- all hydroxides are insoluble, except those of Group 1 metals, barium and ammonium
Primary standard
- It must be obtainable in very pure form
- It must have a known formula
- It must be stable; that is, its composition must not change over time due to the loss or gain of moisture or reaction with the air.
- Preferably, it should have a relatively high molar mass so that weighing errors are minimised.
- Preferably, it should be inexpensive.
Secondary standard
Standard solutions may be prepared by dissolving a known mass of a primary standard in a known volume of solution.
Endpoint
During a titration, the point at which the indicator changes colour is called the endpoint.
