CHEMISTRY FINAL ACS EXAM 2026
QUESTIONS AND ANSWERS
Accuracy? - answerCloseness of measurements to the TRUE VALUE of what is being
measured
Precision? - answerCloseness of a SET of measurements
How do you calculate Percent Error? - answerI experimental-accepted I
____________________ x 100
accepted value
Are zeros infront of non-zero digis significant? - answerNope!
ex: 0.0071 is only 2 sig figs
Are zeros at the end of a number and to the right of the decimal significant? -
answerYep!
ex: 9.100 is 4 sig figs
Addition/Subtraction in regards to sig figs? - answerRound numbers to the least number
of decimal places
Multiplaction/Division in regards to sig figs? - answerRound answers to the least amount
of sig figs
# of e- equal - answerthe # of p+
Atomic Mass? - answerNumber of protons in the nucleus (number on the left bottom
corner of the chemical symbol)
Atomic Mass Number? - answerNumber of protons and neutrons (number on the left
upper corner of the chemical symbol)
Isotope? - answerAtoms of the same element, but with different masses (different
number of neutrons)
STUDY ELECTRON CONFIGURATIONS - answerSTUDY ELECTRON
CONFIGURATIONS
Do columns or rows in the Periodic Table have similar patterns? - answerColumns (the
"groups") have repeating patterns?
Which area of the Periodic Table has greater metallicness? - answerLeft and down has
greater metallicness
, Which area of the PT has greater atomic size? - answerLeft and down has a greater
atomic size
Which area of the PT has greater ionization energy? - answerRight side and up has
greater ionization energy
Which area of the PT has greater electronegativity? - answerRight side and up has
greater electronegativiy, except the Noble Gases of 0 electronegativy
Ionic Bonding? - answerMetal and a nonmetal. Give/take electrons
Covalent bonding? - answerNonmetal and a nonmetal. Share electrons.
VSEPR Theory? - answerValence Shell Electron Pair Repulsion
aka Valence e- pairs stay as far apart as possible
How do you determine polarity? - answerUse the chart that has electronegativity values,
then subtract the elements in the compound from each other.
Is water polar? - answerYes!
Combination Reaction? - answerA + B --> AB
Decomposition Reaction? - answerAB --> A + B
Single Replacement Reaction? - answerAB + C --> AC + B
Double Replacement Reaction? - answerAB + CD --> AD + CB
Combustion Reaction? - answerC + H + O --> H2O + CO2 always
Avogadro's Number? - answer6.022 x 10^23 particles = 1 mole
Molar Mass? - answergram/mole
Mole to Volume? - answer1 mole = 22.4 L
Empirical Formula vs Molecular Formula? - answerMolecular = the actual number of
atoms in a compound
Empirical = basic ratio, smallest whole numbers of atoms in a compound
Percent Composition? - answerMass element/mass compound x 100
Limiting Reactant? - answerThe reactant which runs out first...meaning it limits how
much product can be made
QUESTIONS AND ANSWERS
Accuracy? - answerCloseness of measurements to the TRUE VALUE of what is being
measured
Precision? - answerCloseness of a SET of measurements
How do you calculate Percent Error? - answerI experimental-accepted I
____________________ x 100
accepted value
Are zeros infront of non-zero digis significant? - answerNope!
ex: 0.0071 is only 2 sig figs
Are zeros at the end of a number and to the right of the decimal significant? -
answerYep!
ex: 9.100 is 4 sig figs
Addition/Subtraction in regards to sig figs? - answerRound numbers to the least number
of decimal places
Multiplaction/Division in regards to sig figs? - answerRound answers to the least amount
of sig figs
# of e- equal - answerthe # of p+
Atomic Mass? - answerNumber of protons in the nucleus (number on the left bottom
corner of the chemical symbol)
Atomic Mass Number? - answerNumber of protons and neutrons (number on the left
upper corner of the chemical symbol)
Isotope? - answerAtoms of the same element, but with different masses (different
number of neutrons)
STUDY ELECTRON CONFIGURATIONS - answerSTUDY ELECTRON
CONFIGURATIONS
Do columns or rows in the Periodic Table have similar patterns? - answerColumns (the
"groups") have repeating patterns?
Which area of the Periodic Table has greater metallicness? - answerLeft and down has
greater metallicness
, Which area of the PT has greater atomic size? - answerLeft and down has a greater
atomic size
Which area of the PT has greater ionization energy? - answerRight side and up has
greater ionization energy
Which area of the PT has greater electronegativity? - answerRight side and up has
greater electronegativiy, except the Noble Gases of 0 electronegativy
Ionic Bonding? - answerMetal and a nonmetal. Give/take electrons
Covalent bonding? - answerNonmetal and a nonmetal. Share electrons.
VSEPR Theory? - answerValence Shell Electron Pair Repulsion
aka Valence e- pairs stay as far apart as possible
How do you determine polarity? - answerUse the chart that has electronegativity values,
then subtract the elements in the compound from each other.
Is water polar? - answerYes!
Combination Reaction? - answerA + B --> AB
Decomposition Reaction? - answerAB --> A + B
Single Replacement Reaction? - answerAB + C --> AC + B
Double Replacement Reaction? - answerAB + CD --> AD + CB
Combustion Reaction? - answerC + H + O --> H2O + CO2 always
Avogadro's Number? - answer6.022 x 10^23 particles = 1 mole
Molar Mass? - answergram/mole
Mole to Volume? - answer1 mole = 22.4 L
Empirical Formula vs Molecular Formula? - answerMolecular = the actual number of
atoms in a compound
Empirical = basic ratio, smallest whole numbers of atoms in a compound
Percent Composition? - answerMass element/mass compound x 100
Limiting Reactant? - answerThe reactant which runs out first...meaning it limits how
much product can be made
