Stoichiometry
What must you have to find the correct mole ratio?
A balanced chemical equation.
What is the reactant called that runs out (is used up) first in a chemical reaction?
Limiting reactant.
In a chemical reaction, these numbers can be used to determine the mole ratio of any reactants and/or products.
Coefficients.
The percent yield tells you a relationship between the _________ yield and actual yield of a certain product.
Theoretical yield.
This is the branch of chemistry that deals with mass relationships in compounds and reactions.
Stoichiometry
If you have moles of one substance, what do you use to convert to moles of another substance in the same reaction?
Mole ratio.
What is the reactant called that is left over in a chemical reaction?
Excess reactant.
In the reaction represented by the equation 2Al2O3 --> 4Al + 3O2, this is the mole ratio of Aluminum to Aluminum Oxide.
2:1
After dividing actual yield by theoretical yield, what is the last step.
Multiple by 100.
How do you find molar mass of an element.
Find the atomic mass on the periodic table for that element.
If you are converting from moles to grams what do you do?
Multiply by the molar mass.
How do you know (calculate) which reactant is the limiting reactant?
Use stoichiometry to find the amount of product formed for each. Whichever produces the least amount of the same product is the limiting reactant.
When do you use a mole ratio?
When converting from moles of one substance to moles of another in a chemical reaction.
What is the amount of product produced in the lab called?
Actual yield.
How do you find molar mass of an element.
Find the atomic mass of that element on the periodic table and multiple it by 2.
If you are converting from volume of a gas to moles, what do you do?
Divide by 22.4L.
What is the ingredient that is the limiting reactant if you have 5 cups of flour, 9 eggs and 3 tbs of oil? Given: 2 cups flour + 3 eggs + 1 tbs oil → 4 waffles
Flour.
Which chemical goes on the bottom of a mole ratio?
The one you start with (the known substance).
This is the percent yield of CuS given that you start with ? 15.5 g Na2S and ? 12.1 g CuSO4. The actual amount of CuS produced was ?3.05g . Reaction: Na2S + CuSO4 → Na2SO4 + CuS
42.1%
How do you find the atomic mass of a compound?
Multiply the mass of each element from the periodic table by how many atoms of each element that are present in the compound, then add them all up.
If you have molecules, atoms, formula units, or ions, how will you use to convert to moles?
Divide by Avogadro's number (6.02 x 10^23).
If you need to make 25 ham and cheese sandwiches, what is the limiting reactant?
30 pieces of cheese, 50 slices of bread, 80 pieces of ham
Sandwich: 1 piece cheese, 2 slices bread, 4 pieces ham
Ham.
Which chemical goes on the top of a mole ratio?
The one you are trying to convert to/find.
What is the actual amount of grams produced f the theoretical yield of a reaction is 42.0 grams of product and the percent yield is 75%.
32g
How do you know what to start with when setting up a stoichiometry problem?
Determine the given or known amount of a substance in the reaction.