CH226 Inorganic Chemistry 2
D. Goussev
At least 80% of Test 2 questions (based on material from Lectures 7 to 15) will be selected from the following
list. Note: I do assign partial grades; however, a zero grade will be assigned to any response, even when partly
correct, when the response contains something patently/blatantly absurd, some nonsense. These will be
noted as “NS”, if happen, in your papers.
Test 2 (23% of the CH226 grade) The test questions are listed randomly.
1. Tell the number of valence orbitals and list (by name) all unoccupied valence orbitals in the atom of potassium.
2. Lithium was reacted with an equivalent amount of hydrogen chloride in THF. Draw the structure of the THF complex
formed in this reaction (complete with any charges on the atoms).
3. Potassium was reacted with equivalent amounts of water and a crown ether. Draw the structure of the metal
complex formed in this reaction (complete with any charges on the atoms).
4. (a) Write a balanced equation for the preparation of tert-butyl lithium from 2-chloro-2-methylpropane.
(b) Write a balanced equation for the reaction of tert-butyl lithium with methanol.
5. What happens when an organolithium compound comes in contact with moisture? Write a balanced equation for
this reaction.
6. How many carbons are bonded to every lithium in the structure of methyl lithium? Briefly explain.
7. Write a balanced equation for the reaction of ethyl lithium with acetone and draw the product structure (complete
with any charges on the atoms).
8. What are the concerns (if any) when handling magnesium as (a) fine powder or (b) chunks?
9. The B-F bond distances are significantly different in BF3 vs. [BF4]−. Briefly explain this observation and tell which of
the two species should have the shorter B-F bonds.
10. Arrange all metals from the boron group in the order of increasing their standard reduction potentials, E°(M3/M).
11. Which of the following is the correct formula of the mineral cryolite: Na 2AlF6, Na3AlF6, Na4AlF6? Decide whether the
corresponding boron compound might exist. Explain your decision.
12. Write a balanced reaction equation for beryllium dichloride with a Lewis base of your choice. Make a clear correct
drawing of the product.
13. Calcium carbide is manufactured by heating calcium oxide with carbon.
(a) Write a balanced equation for this reaction
(b) Decide whether the formation of calcium carbide is a redox process. Explain you decision.
14. Explain why aqueous solutions of boric acid are acidic. Write an appropriate reaction equation.
15. Draw the structure of a known M2X6 compound where M is an element from the boron group and X is a halogen.
What should happen if this compound is reacted with a Lewis base? Write a balanced equation for this reaction with
the Lewis base of your choice.
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CH226 Inorganic Chemistry 2
D. Goussev
16. What are the principal structural and electronic differences that you see when looking at boron in the hexagonal and
cubic forms of boron nitride?
17. Correct and rewrite the following sentences: “The standard reduction potentials of the alkali metals, E°(M2+/M), are
all between 2.7 and 3.0 V. Therefore, the alkali metals can oxidize hydrogen and they are tarnished by reaction with
O2 in air. To prevent the reaction with oxygen, the metals should be stored under water.”
18. Acetylene is manufactured by hydrolysis of calcium carbide.
(a) Write a balanced equation for this reaction
(b) Decide whether the formation of acetylene is a redox process. Explain you decision.
19. Draw a fragment of the structure of crystalline beryllium dichloride. Count electrons around beryllium. Decide
whether all Be-Cl bonds are the same (indistinguishable), or not, in this material.
20. Why aluminum is resistant to air and water, even though the element is a good reducing agent (E°(Al3/Al) = –1.66
V)?
21. Explain why dissolving boron trifluoride together with hydrogen fluoride in anhydrous diethyl ether should produce
a strong acid. Draw the structure of the product (complete with any charges on the atoms).
22. Replace all carbons of benzene by boron and nitrogen to obtain an isoelectronic compound. Produce clear correct
structural drawings for both compounds.
23. Replace all carbons of cyclohexane by boron and nitrogen to obtain an isoelectronic compound. Produce clear
correct structural drawings for both compounds.
24. Draw the structures of borazine and the product of reaction of borazine with HCl.
25. Write balanced equations for the following reactions (complete with any charges on the atoms).
a. Potassium with ethanol
b. Sodium hydroxide with aluminum hydroxide
c. Lithium oxide with water
d. Sodium borohydride with an equivalent amount of hydrogen chloride
e. Lithium with water
f.
Lithium with nitrogen gas
g. Sodium with hydrogen gas (upon heating)
h. Sodium with HC≡CH
i.
j.
Calcium hydroxide with carbon dioxide
Calcium with nitrogen gas (upon heating)
k. CaF2 with sulfuric acid
l.
Beryllium hydroxide with sodium hydroxide
m. Beryllium hydroxide with sulfuric acid
n. BeCl2 with water
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CH226 Inorganic Chemistry 2
o. [Be(H2O)4] with an equivalent amount of sodium hydroxide
2
D. Goussev
p. BeF2 with potassium fluoride
q. Hydrolysis of BeCl2
r.
Magnesium with bromine
t.
Diborane with carbon monoxide
s. Diborane with lithium hydride
u. Diborane with oxygen gas
v. Boron trifluoride with dimethyl ether
w. Aluminum trifluoride with sodium fluoride
x. Aluminum with iron(III) oxide (the thermite process)
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