C4

Chemical Symbols

Al - Aluminum, B - Boron, S - Sulfur, N - Nitrogen, Hg - Mercury, Ca - Calcium, Ne - Neon, P - Phosphorus, Cu - Copper, He - Helium, Si - Silicon, K - Potassium, I - Iodine, Fe - Iron, Ag - Silver, Na - Sodium

Common Compounds

NH3 - ammonia, C2H5OH - ethanol, Ca(OH)2 - calcium hydroxide, C6H12O6 - glucose, CO2 - carbon dioxide, H2O - water, HNO3 - nitric acid, Na2CO3 - sodium carbonate, CuSO4 - copper sulphate, H2SO4 - sulfuric acid, HCl - hydrochloric acid, NaOH - sodium hydroxide

Formulae of Ionic Substances

Shows ratio of no. of ions in ionic compound, Size of charge on ion → measure of valency or combining power, Elements can have two ions with different valencies, Can form different compounds, Distinguish different ions with Roman numerals, Charge of element:oxidation state

Molecular Formula

Organic compound:one/more carbon atoms covalently bonded to other element atoms, Common:hydrogen, oxygen, nitrogen, Convention, C2H4BrCl, First:carbon, Second:hydrogen, Third:other elements -> alphabetical order

Ionic Compound

Ions:charged particles (atoms or molecules), Cations:atom with positive charge, Anion:atom negative charge, Monoatomic ion:one atom, Polyatomic ion:two or more atoms covalently bonded together, "Cross-over" method, Work out formula of compound, Swap vacancies. Vacancy of 1 Element after symbol of 2 element:vice versa, Aluminium Sulfide, Valency is A = 3 and S = 2, So the chemical formula is Al2S3, Method, Write vacancies of each ion, Switch numbers

Chemical Equations

Ionic equations, Different to chemical equation:only show species taking part in reaction, Has spectator ions → not in ionic equation, Do not change state, ex. Chemical:NaCl(aq) + AgNO3(aq) - AgCl(s) + NaNO3(aq), Ionic:Cl-(aq) + Ag+(aq) - AgCl(s), Must balance no. of atoms + same overall charge on each side

Relative Atomic Mass

Relative atomic mass (r.a.m (one element)), Mass of atoms compared with mass of carbons (12) atom, Each element = different, R.A.M:larger of two numbers in periodic table, Not always whole number, Average relative atomic mass, All isotopes of each element, Relative formula mass (r.f.m (multiple elements)), Sum of relative atomic masses of all elements in substance formula, Compounds (H2O)

Mole

Avogadro’s constant:6 x 10^23 atoms, ions or molecules, 6 x 10^23 atoms of magnesium = 1 mole of magnesium, There are 6 x 10^23 atoms of one element in 1 mole of that element, which is equal to the element’s atomic mass in grams, R.A.M/ R.F.M in g = 1 mole (6 x 10^23 atoms)

Calculating Moles

R.A.M/ R.F.M in g = 1 mole (6 x 10^23 atoms), Mass (g) = no. of moles x R.A.M/R.F.M (mass of 1 mole), Steps, Write 2 things you have from triangle, For R.F.M → calculate first, Calculate, Include units

Moles & Gases

Use volume → measure no. of moles in gas, 1 mole of gas = 24dm^3 (24 litres):when room temp + pressure (rtp), Volume of gas (dm^3) = no. of moles x 24

Moles & Solutions

No. of moles = concentration (mol/ dm^3) x volume (dm^3), N=CV, Keep units dm^3, cm^3 / 1000 = dm^3, 1 molar solution:1 mole of substrate dissolved in water + solution = 1dm^3 (1000cm^3)

Moles & Chemical Equation

Balanced equation shows no. of moles in products + reactants, ex. 2Mg + O2 → 2MgO, 2 moles magnesium, 1 mole oxygen, 2 moles magnesium oxide

Law of Conservation of Mass

Limiting reactant, Chemical reaction stops when