Pre test unit 8

Empirical formula

the simplest whole number ratio of atoms in a compound

how to convert to empirical

1. convert whats given to mols (% →) g→mol

2. divide by smallest mole number to find whole number ratio

3. use ratio for subscripts

Molecular formula

actual number of each type of atom present, ratio of empirical formula

Stoichiometry

the coefficients of a balanced chemical equation reveal the ratio of numbers of moles of reactants used to the number of moles of products made.

Stoich of gasses with same T and P

since equal number of products, can shortcut, coefficients directly give gas vol ratios as well as mol ratios

Stoich gasses not at stp

must use ideal gas law (PV = nRT)

Percent yield

(Experimental/Theoretical) \* 100

What is the excess reactant

the reactant of which there will be an excess after reaction

What is the limiting reactant

the reactant that will be fully used up in a chemical equation