Chemical formulae, equations and calculations Flashcards
how do you balance equations?
you need to make sure there are the same number of each element on each side of the equation and if there isn’t use big numbers at the front of a compound to balance it
how do you calculate the relative formula mass (Mr) of a compound?
it is the sum of the relative atomic masses of atoms in. the numbers shown in the formula
what are chemical amounts measured in?
in moles (mol)
what is the mass of one mole of a substance in grams equal to?
its relative formula mass
how do you calculate a mole?
mole = mass/ relative atomic mas
how do you calculate mass?
mass = moles x relative atomic mass
how do you calculate percentage yield?
percentage yield = amount of product produced/ maximum amount of product possible x 100
how do you calculate the mass of oxygen?
mass oxygen = mass magnesium oxide - mass magnesium
how do you calculate the moles magnesium?
moles magnesium = mass magnesium/ molar mass magnesium
how do you calculate the moles of oxygen?
moles oxygen = mass oxygen/ molar mass oxygen
what is a molecular formula?
the number of atoms of each element in a compound
what is an empirical formula?
the simplest whole number ratio of atoms of each element in a compound
how do you calculate the empirical formula?
you simplify an equation as much as you can
how do you calculate the molecular formula?
molecular formula = empirical formula x molecular mass of empirical formula
how do you calculate the concentration of a solution?
concentration = mass of solute/ volume
