If it’s acid + polyatomic ion (oxyacid) then change endings -ate→ -ic acid -ite→ -ous acid EX. nitrous acid nitric acid Ionic, polar, and nonpolar bonds If 2.0 it’s ionic If 2.0 it’s polar covalent If 0.4 it’s polar covalent If < 0.4 it’s nonpolar A polar molecule has a partial positive and partial negative side Polar covalent bonds form when not all atoms that share electrons attract them equally. Molecule Shape, Bond angles, and VSEPR Theory VSEPR- Valence Shell Electron Pair Repulsion Model, an arrangement that minimizes the repulsion of shared and unshared pairs of electrons around a central atom. Moles & Molar Conversions Avogadro’s Number = 6.02 1023 particles Molar mass – mass of one mole of a compound Molar mass is calculated by adding together the masses of all atoms in a compound EX. Molar mass of H2O = mass O + mass H + mass H -or- mass O + (2 mass H) 16.0g + 1.01g + 1.01g = 18.0 g/mole -OR- 16.0g + (2 1.01g) = 18.0 g/mole Mole Conversions - it is possible to convert between moles, mass, volume (of gas), or representative particles using conversion factors and dimensional analysis to calculate number of moles and then convert to any other unit shown in the diagram below: Percent Composition, Empirical & Molecular Formulas Percent composition - relative measure of the mass of each different element present in a compound Empirical Formula - the simplest number ratio of atoms present in a compound Calculate from the percent composition, using the following poem: Percent to Mass* Mass to Mole Divide by Small Then Multiply ‘til Whole! Molecular Formula - shows the number of each type of atom in a molecule.
Molecular formula is a whole number multiple of the empirical formula. To determine molecular formula: Divide molecular mass by mass of empirical formula. Multiply the empirical formula by the factor calculated in step 1 Scientists Democritus- first person to say matter was not infinitely divisible Lavoisier- law of conservation of mass (says that the total mass of the substance in a chemical reaction cannot change) Proust- law of definite proportions ( every compound has a fixed proportion) Dalton- law of multiple proportions (If two elements form more than one compound between them, then the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers), also developed the first atomic theory Thomson- discovered electrons Rutherford- gold foil experiment that discovered the atom was mostly empty space, positive particles called protons were in the center or nucleus, and that electrons orbit the nucleus, Millikan- determined that the electron’s charge as -1 and found the mass on an electron Chadwick- discovered neutron and that they have no charge and are needed to stabilize the nucleus. Becquerel- discovered radioactivity Bohr- came up with idea of grounded and excited states Plank- came up with plank’s constant and a relationship between frequency and energy Heisenberg- uncertainty principle states that it is impossible to know the exact velocity and position of a particle at the same time Schrodinger- came up with an equation that treats electrons as waves Pauli- electron in the same orbital have different spins Aufbau – electrons will fill the lowest energy level first Hund- each orbital in an energy level must have an electron before it starts to pair Mendeleev- created the first periodic table, was organized by mass of the element Mosley-discovered each atom has a unique positive charge in the nucleus and created the modern periodic table based off atomic number Lab Equipment