Question | Answer |
the hyphenated symbol for the 'standard' isotope used to define the relative (atomic) mass scale, whole mass is defined as 12.000000, is ___ | C-12 |
sum of the masses of atoms in a formula unit of an ionic compound is called ___ mass | formula |
sum of the masses of atoms in a molecule of a covalent compound is called ___ mass | molecular |
abbreviated (1-letter) unit for measuring atomic/formula/molecular mass, defined as one-twelfth the mass of a C-12 isotope, is the ___ (aka a.m.u. or 'dalton') | u |
the atomic, formula, or molecular mass measured in grams is called a ___ mass | gram |
the amount of substance containing 6.022 x 10^23 representative particles of a chemical (atoms/formula units/molecules) is a ___ | mole |
representative particles (building blocks) of most elements | atoms |
representative particles (building blocks) of covalent compounds and diatomic elements | molecules |
representative particles (building blocks) of ionic compounds | formula units |
the honorary name given to 6.022 x 10^23, the # of representative particles in 1 mole, is ___ number | Avogadro's |
the portion of a compound contributed by each element is ___ composition | percent |
simplest whole # ratio of atoms in the formula of a compound is the ___ formula | empirical |
If solving for empirical formula from % composition and find coefficient ratio of 1 to ?.33 or 1 to ?.67, which multiplier is used? | 3 |
If solving for empirical formula from % composition and find coefficient ratio of 1 to 1.25, or 1 to 1.75, which multiplier is used? | 4 |
If solving for empirical formula from % composition and find coefficient ratio of 1 to 1.5, which multiplier is used? | 2 |
If the empirical formula for a compound is C2H5, and its molecular mass is 58.0, then what is the value of "X" used to find the molecular formula? | 2 |
total atoms in formula (NH4)2SO4 | 15 |
total atoms in formula Pb3(PO4)4 | 23 |
steps to find empirical formula from percent composition | 1. pretend you have 100 g of compound
2. change % to grams
3. change g to moles
4a. divide by smallest mole
4b. find multiplier if needed
5. use #'s as subscripts |
how to find molecular formula from empirical formula and molar mass | 1. (E.F. mass)X = molar mass
2. solve for X
3. use X to multiply all subscripts |
total atoms in the formula CuSO4•5H20 | 21 |