Chapter 3: Stoichiometry

Question 1

Stoichiometry

Answer 1

conservation of mass!

Quantitative relationships (ratios) between parts of chemical formulas and/or chemical equations

Question 2

Types of chemical reactions

Answer 2

Combinations, decomposition, combustion

Question 3

Combustion Reaction Properties

Answer 3

Usually involves burning hydrocarbons (things with H, C, and/or O) in O2

Products always include H2O and CO2 (unless incomplete combustion: you get CO also because reactants didn’t have enough O2)

Question 4

Combination Reactions

Answer 4

Multiple things become fewer things;

When they’re between metals and non-metals, they usually make solids (ionic compounds)

Question 5

Incomplete Combustion

Answer 5

When combustion reaction products include CO because reactants didn’t have enough O2

Question 6

Formula Weight

Answer 6

The sum of the atomic weights of the atoms in a chemical formula

Question 7

Molecular Weight

Answer 7

The TOTAL sum of the atomic weights of the atoms in a MOLECULAR formula

Question 8

Avogadro’s Number

Answer 8

6.02E23

Quantity; formula units of a substance (like a dozen)

Question 9

Molar Mass

Answer 9

Number of grams per mole of an element

Mass of a substance in moles

Question 10

Empirical Formula

Answer 10

A chemical formula expressed with the smallest ratios of each of it’s components

Calculated by using the % composition of each component and then calculation their respective moles

Question 11

Limiting Reactant

Answer 11

The reactant in a reaction that will run out first

Question 12

Theoretical Yield

Answer 12

Amount of product you should be able to get from a reaction, based on its limiting reactant

Question 13

Percent Yield

Answer 13

(actual yield/theoretical yield)*100