CHEM 101 EXAM REVIEW
QUESTIONS WITH ACCURATE
SOLUTIONS 2026
▶ ionic compounds. Answer: cations and anions (pos and neg)
written Cation Anion
ex: write the formula for salt made of calcium + F
= Ca^+2 F^-1 so CaF2 (need to balance charges)
formed by metals + nonmetals
▶ ionic bond. Answer: between + and - charge
▶ covalent bond. Answer: between non metals
atom bonded to another atom of the same type
share electrons in order to get to 8 valence e- (except H and He get 2)
▶ naming covalent compounds. Answer: prefix: 1 mono, 2 di, 3 tri, 4 tetra,
5 penta, 6 hexa, 7 hepta, 8 octa, 9 nona, 10 deca
ending in "ide"
▶ transition metals. Answer: always + but some elements can have
multiple charges
▶ naming ionic compounds. Answer: (cation) (anion + ide)
NaCl = Sodium Chloride
Copper (II) Chloride = CuCl2
TiCl4 = Titanium (IV) Chloride
**transition metals usually have charge written as roman numeral
▶ common bonding patterns. Answer: hydrogen = 1 bond
carbon = 4 bonds
nitrogen = 3 bonds, 1 LP
, oxygen = 2 bonds, 2 LP
Halogens = 1 bond, 3 LP
▶ when drawing lewis structures, the atom that can form the most bonds is
usually in the center. Answer: ex: CCl4 ---> the C is in the middle, the Cl
surround it
▶ Polyatomic ions. Answer: NH4+ = ammonium
OH- = hydroxide
NO3- = nitrate
NO2- = nitrite
HCO3- = bicarbonate
CN- = cyanide
SO4-2 = sulfate
SO3-2 = sulfite
CO3-2 = carbonate
PO4-3 = phosphate
▶ write the formula for lead (II) sulfate. Answer: the (II) gives you the
charge.
Pb^+2 SO4^-2 = PbSO4
▶ write the formula for iron (III) nitrate. Answer: Fe^+3 NO3^-
Fe(NO3)3 ---> Fe has pos 3 charge, so NO3 ^-needs a pos 3 charge so it
is balanced. (so Fe has pos 3, NO3- has -3)
▶ isomers. Answer: molecules with the same atoms, different connectivity
ex: C3H6 can be drawn in different ways, don't always have the same
functional group
▶ VESPR theory. Answer: because electron pairs repel, molecules adjust
their shapes so that valence electrons pairs move as far apart as possible
▶ electron geometry. Answer: each bond (1, 2, 3) and each LP count as
one area of electrons
a) Four areas of electrons = tetrahedron (109.5)
b) 3 areas of e- = trigonal planar (120)
c) 2 areas of e- = linear (180)
QUESTIONS WITH ACCURATE
SOLUTIONS 2026
▶ ionic compounds. Answer: cations and anions (pos and neg)
written Cation Anion
ex: write the formula for salt made of calcium + F
= Ca^+2 F^-1 so CaF2 (need to balance charges)
formed by metals + nonmetals
▶ ionic bond. Answer: between + and - charge
▶ covalent bond. Answer: between non metals
atom bonded to another atom of the same type
share electrons in order to get to 8 valence e- (except H and He get 2)
▶ naming covalent compounds. Answer: prefix: 1 mono, 2 di, 3 tri, 4 tetra,
5 penta, 6 hexa, 7 hepta, 8 octa, 9 nona, 10 deca
ending in "ide"
▶ transition metals. Answer: always + but some elements can have
multiple charges
▶ naming ionic compounds. Answer: (cation) (anion + ide)
NaCl = Sodium Chloride
Copper (II) Chloride = CuCl2
TiCl4 = Titanium (IV) Chloride
**transition metals usually have charge written as roman numeral
▶ common bonding patterns. Answer: hydrogen = 1 bond
carbon = 4 bonds
nitrogen = 3 bonds, 1 LP
, oxygen = 2 bonds, 2 LP
Halogens = 1 bond, 3 LP
▶ when drawing lewis structures, the atom that can form the most bonds is
usually in the center. Answer: ex: CCl4 ---> the C is in the middle, the Cl
surround it
▶ Polyatomic ions. Answer: NH4+ = ammonium
OH- = hydroxide
NO3- = nitrate
NO2- = nitrite
HCO3- = bicarbonate
CN- = cyanide
SO4-2 = sulfate
SO3-2 = sulfite
CO3-2 = carbonate
PO4-3 = phosphate
▶ write the formula for lead (II) sulfate. Answer: the (II) gives you the
charge.
Pb^+2 SO4^-2 = PbSO4
▶ write the formula for iron (III) nitrate. Answer: Fe^+3 NO3^-
Fe(NO3)3 ---> Fe has pos 3 charge, so NO3 ^-needs a pos 3 charge so it
is balanced. (so Fe has pos 3, NO3- has -3)
▶ isomers. Answer: molecules with the same atoms, different connectivity
ex: C3H6 can be drawn in different ways, don't always have the same
functional group
▶ VESPR theory. Answer: because electron pairs repel, molecules adjust
their shapes so that valence electrons pairs move as far apart as possible
▶ electron geometry. Answer: each bond (1, 2, 3) and each LP count as
one area of electrons
a) Four areas of electrons = tetrahedron (109.5)
b) 3 areas of e- = trigonal planar (120)
c) 2 areas of e- = linear (180)
