Stoich

What is the mole ratio of H2O to H3PO4 in the following chemical equation? P4O10 + 6H2O -> 4H3PO4

3, 2

In the equation 2Al2O3 -> 4Al + 3O2, what is the mole ratio of aluminum to oxygen?

4:3

How many mole ratios can be correctly obtained from the chemical equation 2Al2O3(l) -> 4Al(s) + 3O2(g)

6

In the formation of silicon carbide represented by the chemical equation SiO2(s) + 3C(s)-> SiC(s) + 2CO(g), 8 mol of each reactant are available for the reaction. What substance is the excess reactant?

SiO2(s)

If the percentage yield for a chemical reaction is 80.0%, the

actual yield is 80.0 g for every theoretical yield of 100 g

To determine the limiting reactant in a chemical reaction involving known masses of the two reactants, which of the following would be most useful?

calculating the mass of a single product formed from each reactant

For a chemical reaction, percentage yield represents the

efficiency

Actual yield must be determined by

experiments

In most chemical reactions the amount of product obtained is

less than the theoretical yield

The actual yield of a chemical reaction is generally

less than the theoretical yield

The participation of reactants in a chemical reaction is restricted by the

limiting reactant

Which expression can be used to solve a mass-to-mole conversion for the equation 2HCl -> H2 + Cl2?

mass HCl x 1 mol HCl x 1 mol Cl2 molar mass HCl 2 mol HCl

The expression mass x 1 mol/molar mass has the unit

mol

A balanced chemical equation allows one to determine the

mole ratio of any two substances in the reaction

Which of the following factors does not affect the actual yield of a reaction

particles no longer reacting with each other

Which of the following mathematical expressions correctly states the relationship among percentage yield, actual yield, and theoretical yield?

percentage yield = actual yield/theoretical yield x 100 theoretical yield = actual yield/percentage yield x 100

The coefficients in a chemical equation represent the

relative numbers of moles of reactants and products

Fewer steps are required to solve stoichiometry problems when

the reactant is given in moles and the product is sought in moles

The limiting reactant of a reaction can be used to calculate the

theoretical yield