Chemistry - Ch. 11

Terminology

100

What is the study of the mathematical relationships between the amounts of reactants and products in a chemical reaction?

Stoichiometry

200

In a reaction, what is the reactant that is completely used up?

Limiting reactant

300

What is Avagadro's number?

6.022 * 10²³

400

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

500

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

Math!

100

How many atoms are in 83 mol of Antimony?

5.0 * 10²⁵ atoms

200

What is the molar mass of potassium phosphate?

196.27 g/mol

300

What is the empirical formula for an unknown sample whose composition is 38.4% Carbon, 10.0% Hydrogen, and 51.6% Oxygen?

CH₃O

400

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

500

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?

(1) PbO

(2) 14.25 g ZnO

(3) Zn, 27.6 g left

More Math!

100

What is the mass of 2.6 mol of Iodine?

329.94 g

200

How many grams of Magnesium are in 8439.32 g of magnesium nitrite?

1112.99 grams

300

What is the ratio of water to nitric acid in "H₂O + N₂O₅ → 2HNO₃?

1:2

400

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

500

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%