Terminology
What is the study of the mathematical relationships between the amounts of reactants and products in a chemical reaction?
Stoichiometry
How many atoms are in 83 mol of Antimony?
5.0 * 1025 atoms
What is the mass of 2.6 mol of Iodine?
329.94 g
Limiting reactant
What is the molar mass of potassium phosphate?
196.27 g/mol
How many grams of Magnesium are in 8439.32 g of magnesium nitrite?
1112.99 grams
What is Avagadro's number?
6.022 * 1023
What is the empirical formula for an unknown sample whose composition is 38.4% Carbon, 10.0% Hydrogen, and 51.6% Oxygen?
CH3O
What is the ratio of water to nitric acid in "H2O + N2O5 → 2HNO3?
1:2
What is the difference between theoretical yield and actual yield?
Theoretical yield - the maximum amount of product that could be produced from a given amount of reactant
Actual yield - the measured amount of product at the end of a reaction
Consider the following reaction: "Li2S + CoCl2 → CoS + 2LiCl."
If 74.12 g of lithium sulfide is used, how many grams (and moles) of lithium chloride are produced?
136.9 g LiCl
3.23 mol LiCl
You have a sample of Na2CO3. What is the percent composition of each element in the compound?
43.4% Sodium
11.3% Carbon
45.3% Oxygen
Differentiate between empirical formulas, structural formulas, and molecular formulas?
Empirical formula - gives the elements that are present and gives the simplest whole-number ratio of atoms in a compound
Molecular formulas - indicates the types and numbers of atoms found in a molecule, ion, or formula unit
Structural formulas - show where things are
Consider the following equation: "PbO + Zn → ZnO + Pb".
39.07 g of each reactant is used.
(1) What's the limiting reactant?
(2) How many grams of zinc oxide would be produced?
(3) What's the excess reactant? How many grams of it are left?
(2) 14.25 g ZnO
(3) Zn, 27.6 g left
You are studying the decomposition of mercury (II) oxide into mercury and diatomic oxygen. You start with 29.0 grams of mercury (II) oxide. What is the theoretical yield of mercury?
If you get 49.3 g of mercury, what is your percent yield?
Actual yield: 53.7 g Hg
Percent yield: 91.8%