Chem Test Ch. 11-12 Flashcards
chemical equation
a representation of a chemical reaction
balanced equation
each side has the same number of atoms of each element and mass is converved
combination (synthesis)
element + element -> compound
decomposition
compound -> element + element
single - replacement
element + compound -> compound + element
anionic
metals or hydrogen will switch
cationic
nonmetals or groups 17 halogens will switch
combustion
hydrocarbon + O2 -> CO2 + H2O
stoichiometry
calculation of quantities in chemical reactions is a subject of chemistry
mole ratio
a conversion factor derived from the coefficients of a balanced chemical equation interpreted in terms of moles
limiting reagent
the reactant that determines the amount of product that can be formed
excess reagent
the reactant that is not completely used up
theoretical yield
maximum amount that can be formed
actual yield
the amount that actually forms
percent yield
ratio of yields: actual/theoretical x 100%
List the 7 diatomic gases
HONClBrI
Write the formulas for the seven diatomic gases
H2, N2, O2, F2, Cl2, Br2, I2
List the three conversion factors used in stoichiometry
- Molar mass conversion factor (g/mol)
- Avogadro’s # conversion factor (particles/mol)
- Volume conversion factor for gases at STP (22.4L/mol)
Write the formula for theoretical yield
theoretical yield = actual or experimental yield x molar mass of desired product/molar mass of reactant x coefficients of desired product/coeddiecients of reactant
How is the actual yield obtained?
The actual yield is obtained through experimental measurements conducted in a laboratory setting.
How is the theoretical yield obtained?
The theoretical yield is obtained through stoichiometric calculations based on the amount of reactants used in a chemical reaction.
What is the maximum value for percent yield?
100%
Substances on the right of chemical equation are called
products
Substances on the left of the chemical equation are called?
reactants
What do the coefficients represent in a chemical reaction?
stoichiometric ratios of reactants and products in a chemical reaction.
Compare quantities between two compounds in terms of mass(grams), moles, and molecules.
Mass: Convert between grams using molar mass.
Moles: Convert between moles using Avogadro’s number.
Molecules: Convert between molecules using Avogadro’s number.
Predict the products of a combustion reaction
The products of a combustion reaction typically involve carbon dioxide (CO2) and water (H2O).
Predict the products of single replacement reaction
The products of a single replacement reaction depend on the specific reactants involved.
Predict the products of a double replacement reaction
The products of a double replacement reaction are typically two new compounds
Distinguish between cationic and anionic single replacement
In a cationic single replacement, a metal (which forms cations) replaces another metal in a compound. For example: Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s).
In an anionic single replacement, a nonmetal (which forms anions) replaces another nonmetal in a compound. For example: Cl2(g) + 2NaBr(aq) → 2NaCl(aq) + Br2(l).
