Chem 300
Practice questions for Exam #2
1. Answer the following questions.
a. Which subshells can occupy the n=4 shell?
b.
What is the maximum number of electrons that can occupy a 3p orbital?
c.
What is the maximum number of electrons that can occupy a 3d orbital?
d.
What is the maximum number of electrons that can occupy a 4d subshell?
2. Which element has the SMALLEST atomic radius?
a) Fr
b) Sr
c) Al
d) S
e) F
3. Which of the following elements would exhibit chemical properties most similar to arsenic (As)?
a) Ge
b) Zn
c) P
d) Kr
e) Se
4. Which ion is isoelectronic with Ar?
a) Fb) O2c) K+
d) Mg2+
e) Na+
5. Write the FULL electron configuration for each of the following atoms and show its Lewis Structure
Full electron configuration
Lewis Structure
a) C
b) S
c) Br
6. Write the electron configuration for each of the following atoms and ions. You may use the noble gas core.
a) Na+
b) Ca2+
c) O2-
d) Ta
e) Au
7. Write the formula for the ionic compound formed from each of the following types of ions and NAME each
compound.
Chemical Formula
Chemical Name
2+
2a) Mg and S
b) Na+ and CO32c) Al3+ and SO42d) Cu2+ and Bre) NH4+ and PO43-
8. Complete the table below.
Chemical Formula
Chemical Name
Fe(NO3)2
Chloric acid
H2SO4
Carbon tetrachloride
Pb(IO4)2
Chromic acid
9. Complete the table below.
Compound
Lewis structure
Electron
Geometry
Molecular
Geometry
Molecular
Polarity
NH3
CH4
SO2
10. What is the molar mass of magnesium nitrate?
11. How many moles of magnesium nitrate are in a 275 Mg sample? (Mg = megagrams)
12. How many nitrogen atoms are in 0.25 moles of magnesium nitrate?
13. How many grams of magnesium nitrate are in 0.75 moles of magnesium nitrate?
14. How many oxygen atoms are in 275 pg of magnesium nitrate? (pg = picograms)
15. How many p electrons are in 12.5 g of magnesium nitrate?
16. A compound with a molar mass of 110 g/mole consists of 65.45% C, 5.492% H and 29.06% O on a mass basis.
Determine the molecular formula of this compound.