IMF Test

Intermolecular Forces :weak, temporary attractions between molecules (not bonds, much weaker)

Types of Intermolecular Forces: Ion-Dipole > Hydrogen Bonding > Dipole Dipole > Van Der Waals

Ion Dipole - occurs between ions and polar molecules

Hydrogen Bonding - occurs between H - O,N,F very polar bond

Dipole Dipole - exists between two polar molecules

Van Der Waals - occurs between all substances only IMF for nonpolar molecules also known as London Dispersion

IMF Properties - larger molecules have stronger IMF's substances with strong IMF's are often solids or liquids at room temperature

Moles - Avogadros Number 1 Mole = 6.022 x 10^23 atoms/molecules the mole is a way to count particles molar mass - mass of 1 mole of a substance in grams unit: grams per mole (g/mol)

mole calculations - use dimensional analysis and follow the mole map

percent composition - the percent by mass of each element in a compound (mass of part/mass of whole) x 100

empirical formula - the simplest, whole number ratio of atoms in a compound

molecular formula - represents the number of atoms present in the molecule

calculating empirical formula - 1: convert given % mass data to grams 2: convert grams to moles without rounding values 3: create mole ratios, divide by the smallest mole number *4: If ratios are not whole numbers, multiply by an integer to get whole numbers

determining molecular formula from empirical formula - 1: divide the molar mass of the molecule by the molar mass of the empirical formula (answer should be an integer) 2: multiply the empirical formula by the intiger