AP Chem Unit 1 Review questions and answers Graded A+

AP Chem Unit 1 Review questions and answers
Graded A+
atomic mass unit - ✅✅the mass of an individual atom or 1 mol of atoms is
sometimes expressed in this unit?


6.022 x 10^23 particles - ✅✅How many particles are in 1 mol of a pure
substance?


Take number of moles and X by Avad's # - ✅✅How do you find the number of
particles in in 9.30 x 10^-3 mol of Na2CO3?


Multiply number of particles in Na2CO3 and X by mol ratio (2 Na = 1 mol Na2CO3)
(X by 2) - ✅✅How do you find the number of Na atoms in 9.30 X 10^-3 mol of
Na2CO3?


(Mass 1 X .RA) + (Mass 2 X .RA).... - ✅✅How do you find the average atomic
mass of an unknown element given mass and relative abundance?


G to moles
Divide by small

Multiply till whole - ✅✅How do you find the empirical formula of a compound
given (g)?


% to g
G to moles
Divide by small

, Multiply till whole - ✅✅How do you find the empirical formula of a compound
given (%)?


Divide the molar mass of molecular by empirical's and use the multiple to X the
subscripts in emp form - ✅✅How do you find molecular formula from an
empirical given the molar mass of the compound?


Compound + O2 => CO2 + H2O
g CO2 to mol X mol ratio of C:CO2
g H2O to mol X mol ratio of H:H2O

Using moles x & y of CxHy, convert to emp form - ✅✅How do you find the
empirical formula if (g) of C and (g) of H2O formed in a complete combustion?


Find the contaminant w/ a higher % O than in Na2O (higher % would cause an incr
in %O).


O MM/Compound MM X 100 = % O - ✅✅How do you find the contaminant if
given % Na, % O but a contaminated sample had a higher % O?


Average mass = (Mass 1 * X) + (Mass 2 * (1-X))

Solve for X, convert to % - ✅✅How do you determine the % abundance for 2
isotopes given the average atomic mass?


Electrons are added to the lowest energy subshells first (Increasing E:
1s2s2p3s3p4s3d4p5s) - ✅✅What is Aufbau's principle?