Mole Quiz

review notes, lab, worksheets

mole

unit of measurement for the amount of substance in a sample (atoms, molecules, ions, etc.)

avogrado’s number

number of atoms in exactly 12 grams of carbon-12; 6.022 × 10²³

mass of one mol of carbon atoms

12 grams

molar mass

total mass of all the elements in a molecule (make sure to “distribute” atoms if there’s parentheses)

calculate the molar mass for Sr(NO₃)₂

approx. 211.64 g/mol

grams to moles

divide by molar mass

moles to grams

multiply by molar mass

moles to atoms

multiply by 6.022 × 10²³

atoms to moles

divide by 6.022 × 10²³

moles to L

multiply by 22.4

L to moles

divide by 22.4

hydrate

when water is loosely bonded to a solid crystal

hydrate notation

dot between ionic compound and water

naming hydrates

ionic compound + prefix (# of H₂O) hydrate

percent composition

percent by mass of each element present in a compound

how to calculate percent composition

find the total molar mass, divide each element’s molar mass by the total, multiply by 100

find percent composition of 1 mole of H₂O

oxygen - 88.9%, hydrogen - 11.1%

empirical formula

formula with the smallest whole-number ratio of the elements

molecular formula

specifies actual number of atoms of each element in a molecule

empirical formula vs. molecular formula in hydrogen peroxide

empirical - HO; molecular - H₂O₂