WorksheetsCHM 101 Exam 2 Practice Problems
Total questions: 20
Worksheet time: 5hrs 0mins
Three students wrote chemical formulas to represent the diagram below. For each
response, indicate if they are correct or not and why.
S3O incorrect formula says 3 S atoms bonded to 1 O atom
S6O18 is incorrect formula says 6 S atoms bonded to 18 O atoms
SO3 correct
How do you tell if a compound is considered ionic or covalent? What characteristics
do you use to make the distinction?
An ionic compound must be made up of ions. What ions make up each of the following:
a. Ca(OH)2 b. Al 2 (CO 3 )3
1 Ca2+ ion and 2OH- ions
2 Al3+ ions and 3CO3'2- ions
Ca1+ ions
AlCO3+ ions
What is the name of Ca(OH)2 ?
(a)
What is the name of S2O4 ?
(a)
What is the formula for tetrachlorine difluoride?
What is the formula for cobalt (III) sulfate?
What is the name of C4H10 ?
(a)
How can we use the periodic table to determine the number of valence electrons an
atom has & the ion charge it forms?
There are two types of ions: cations and anions. What is the difference between the
two? Relate this to protons & electrons.
What is the electron configuration & Nobel Gas electron configuration for copper
(Cu)?
1s2,2s2,2p6,3s2,3p6,4s1,3d10 [Ar] 3d104s1
What are some exceptions to our rules for writing electron configurations (i.e., when
do we break the rules in order to write correct electron configurations)?
Draw the Lewis structures for the trisulfur molecule (S3). Be sure to include all resonance structures that satisfy the octet rule.
Looking at your answer to question 10, for one molecule of S 3 , how many bonding
electrons do you have? How many lone electrons do you have?
How do we use formal charges to evaluate Lewis structures? Can you calculate a
formal charge for individual atoms in a Lewis structure?
What are the differences between the various bond types (polar covalent, non-polar
covalent, and ionic)? How can you use the periodic table to determine which type of
bond you have?
Think about ions, what subatomic particle participates in the ion formation
process? How does adding/removing this subatomic particle impact the atom size?
A chemists analyzed an unknown sample and determined that it had the following percent composition: • Carbon: 49.48% • Hydrogen: 5.19% • Oxygen: 16.48% • Nitrogen: 28.85%. Using this data, determine the empirical formula & the molecular formula. The molecular weight of the compound is 194.19 g/mol.
The empirical formula is C4H5ON2 and the molecular formula is C8H10O2N4.
Calculate the number of molecules of cobalt (II) chloride in 5.427 g
2.517 x 10^22 molecules CoCl2
What are the trends across the periodic table for electronegativity, ionization
energy, electron affinity, and atomic radius?
