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