stochiometry Flashcards
what are 3 general rules when finding limiting and excess reactants
1- deal with calculations in mole and find solutions after
2- ask self if the first reactant in mole is used up how many moles of the second reactant is needed
3- ask self if the second reactant in mole is completely used, how many moles of the first one is required
what is a molecule
2 or more atoms of an element chemically combined
define molecular formula
formula showing the type of elements and the number of atoms within the elements
does molecular formula show the structure
molecular formula only shows the formula and not the structure of the molecule
define empirical formula
the simplest whole ratio of a giant molecule
why is empirical formula used?
when a molecule is too big to be represented by the molecular formula, the smallest whole ration is used which is the empirical formula
what is a compound
a molecule with different type of atoms
why is H20 know both as a molecule and a compound?
molecule
- h20 has 2 of the same atoms being 2 hydrogen atoms
compound
-h20 has 2 of the same atom including an atom oxygen
what is unified atomic mass unit?
1/12 of the mass of carbon-12
define relative atomic mass
the mass of an atom of an element relative to 1/12 of the mass of carbon-12 atom
define relative isotopic mass
the mass of an atom of a specific isotope relative to 1/12 of the mass of carbon-12 atom
what can relative isotopic mass and natural abundance find?
the relative atomic mass of an element
define relative atomic mass in relation to isotope
the average weight of atoms of isotopes of the same element taking into consideration the abundances
define molecular mass
the mass of a molecule of a compound relative to 1/12 of the mass of carbon-12 atom
what is the differences between molecular mass and formula mass?
formula mass is in relation to ionic compounds
