F321 Chemistry Notes

F321
 

Isotopes - Atoms of the same element - same number of protons and electrons - same chemical reactions (speed varies) Physical properties such as melting point and density varies

(Relative atomic mass x Abundance) + (repeat) / 100

+ Protons relative mass 1

Neutrons relative mass 1

- Electrons 1/2000th the mass of a proton

Relative Atomic Mass is the weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of Carbon 12

Relative Isotopic Mass is the mass of an atom of an isotope compared with1/12 of the mass of an atom of Carbon 12

Equations   

Mole the amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon-12 isotope

Number of moles = Mass / Atomic Molecular Mass

Empirical Formula simplest whole number ratio of atoms of each element present in a compound

Mass / Atomic Mass = Moles / smallest number = Ratio

Molar mass Number of atoms of each element in a molecule

 Molecular Mass / Empirical = Number of molecules

 Molecular Formula Number of atoms of each element in a molecule

Avogadro's Law for any gas the number of particles is always the same

Volume of gas (cm3) / 24 (24000) = Number of moles

Concentration x Volume [cm3/1000] = Number of moles

1 Mole is equivalent to 6.023 x 10^23 (Avogadro's number) units of any substance.

Acids

Acid + Metal > Salt + Hydrogen

Acid + Metal Oxide > Salt + Water

Acid + Carbonate > Salt + Water + Carbon dioxide

Neutralisation H+(aq) + OH-(aq) > H2O (l)

Acid + Alkali > Salt + Water

Salt - The H+ ion in an acid has been replaced by a metal ion

Acids - HCl, H2SO4, HNO3 Alkalis (soluble base) - metal oxides, metal hydroxides, ammonia Finding x in hydrated solutions

Mass of solution - mass after heated - Use empirical formula method

Redox / Disproportionation 

Oxidation The number of electrons an element uses to bond to other atoms

Uncombined elements  - Ca, He, O2, Cl2 - Oxidation number of 0  

Combined oxygen - H2O, CO2 - Oxidation number of -2 

Combined hydrogen - HCl - Oxidation number = +1

Ions Li+ = +1, Ca2+ = +2, Cl- = -1 Oxidation number = depends on charge of ion 

Metals generally lose electrons and have an increase in oxidation number to form positive ions - oxidised Non-metals generally gain electrons and have a decrease in oxidation number to form negative ions - reduced 

Oxidation Involves Loss Reduction Involves Gain of electrons

Oxidation is an increase in oxidation number

Reduction is a decrease in oxidation number

Electron Structure

An atomic orbital is a space within an atom that can hold up to two electrons with an opposite spin S-Orbital 2e-  P-Orbital 6e-  D-Orbital 10 e-  F-Orbital 14 e-

Degenerate Orbitals (P, D, F)

The first ionisation energy of an element is the…