chemistry ch. 9
how many mole ratios can be obtained from the following chemical equation? NA(2)S + Cd(NO3)2 -----> 2NaNO(3) + CdS
12
if 8.0 mol As2O3 reacts with excess carbon, the theoretical yeild of the above reaction is
16 mol As
in the chemical equation reaction described by the equation 4Fe(s) + 3O(2)(g) --> 2Fe2o3(s), the mole ratio of iron (III) oxide to iron is
1:2
the number of conversion factors needed to solve a mass-to-mass stoichiometry problem is
3
if in the reaction A+B-->C+D, the quantity of B is insufficient to react with all of A
B is the limiting reactant
measured amount of a product obtained from a reaction
actual yield
the measured amount of product obtained from a chemical reaction is the
actual yield
what is the correct mathematical expression for the relationship among percentage yield, actual yield, and theoretical yield?
actual yield percentage yield= ------------------- x 100 theoretical yield
actual yield is affected by
all of the above
molar mass can be used to relate
all of the above
when a chemical reaction is carried out under ideal conditions, it is implied that
all reactants are completely converted into products
the chemical equation P(4)0(10) + 6H(2)O -----> 4H(3)PO(4) can be interpreted correctly as
both a and b
in a stoichiometric calculation to determine the mass of one substance that will react with a given amount, in moles, of a second substance, you need to know
both the mole ratio of the unknown substance to the given substance and the molar mass of the unknown substance
deals with mass relationships or elements in compounds
composition stoichiometry
substance that is not used up completely in a reaction
excess reactant
the conversion factor used to convert from grams to moles is
inverted molar mass
reactant that limits the amount of the other reactant that can combine and the amount that can form in a chemical reaction
limiting reactant
stoichiometry is the branch of chemistry that deals with elements in compounds and with reactants and products in chemical reactions focusing on
mass relationships
the type of stoichimetry problem that involves the most steps is a
mass-to-mass conversion
what is the unit for the following expression : mass x 1mol/molar mass?
mol
complete the following solution plan: mol of given substance x mol unknown/mol given=
mol of unknown
you are asked to use stoichiometry to solve a problem in which you are given the molar amount of one substance and asked to determine the molar amount of an unknown. which of the following conversion factors should you use to complete the calculation?
molar quantity of the unknown ------------------------------------ molar quantity of the given substance
conversion factor that relates the amounts in moles of any 2 substances involved in a chemical reaction
mole ratio
a balanced chemical equation explicitly provides you with the
mole ratios needed to solve a stoichiometry problem
if the percentage yield of I2 is 80% for the following equation, I205+5CO-->I2+5CO2, then
neither a nor b
ratio of the actual yield to the theoretical yield multiplied by 100
percentage yield
the efficiency of a chemical reaction is best expressed by the
percentage yield
involves mass relationships between reactants and products in a chemical reaction
reaction stoichiometry
in stoichiometry, molar mass is used to
relate the mass of a substance to the amount in moles of that substance
reaction stoichemetry is based on chemical equations and
the law of conservation of mass
which information is not needed to solve a mass-to-mass stoichiometric calculation?
the mass ratio
in the chemical equation wA+xB-->yC+zD, if you know the number of moles of A that react, you can determine
the number of moles of each reactant and product
the number of significant figures in an answer to a stoichiometry problem is determined only by
the number of significant figures of any measured quantities in the problem
molar masses are determined from
the periodic table
if, in the reaction A+B-->C+D, the quantity of B is insufficient to react with all of A
the reaction stops
maximum amount of product that can be produced from a given amount of reactant
theoretical yield