Instructions:  Circle the best answer for each question.

The Reagent Shelf.
These compounds are available as pure substances or in solution, as appropriate for your needs.
 

Acids	Bases	Boron	Carbon	Halogens	Hydrogen
H2SO4 H3PO4 HCl HNO3	Ca(OH)2 KOH NaOH	B(OH)3 B2O3 BF3 Na2B4O7.10 H2O NaBH4 NaBO3.4 H2O	C(s)  CaC2 CO  CO2 Na2CO3 Na2CO3 NaHCO3	Br2 Cl2 I2 KBr  KI  NaCl	CaH2 H2 LiAlH4 NaBH4

 

Metals, Metal Salts	Oxygen	Nitrogen	Phosphorus	Silicon	Sulfur
Cu Cu(NO3)2 Mg MgO MnO2 Zn Zn(NO3)2	H2O H2O2 Na2O O2 O3	KNO3 NaNO2 NH3(aq) NH3(g)	Ca3P2 H3PO3 H3PO4 P(red) P4 P4O10	Si SiCl4	H2S FeS Na2S Na2SO3 NaHSO3 S8 SO2 SO3

HYDROGEN:

1. Which of the following is NOT an important economic use for hydrogen?

A. formation of ammonia
B. hydrogenation of oils
C. formation of syn-gas used in the plastics and adhesives industries
D. purification of water-soluble organic compounds such as acids and alcohols

2 and 3. Recall the electrolysis of water.

2. What gas is produced at the anode?

A. oxygen
B. hydrogen
C. chlorine
D. both hydrogen and oxygen

3. What is the pH at the anode?

A. acidic
B. basic
C. neutral
D. this was not determined

4. What product is expected when calcium hydride is reacted with D2O?

A. 100% H2
B. 100% D2
C. 100% HD
D. 50% H2 and 50% D2
E. 50% HD, 25% H2 and 25% D2

5.  Why did the pringles can burn for awhile and then 'explode'?
 

A. The reaction between hydrogen and air is kinetically slow.
B. At first the flame is not hot enough to ignite hydrogen.
C. The H2 does not make it's way to the top of the can until some of the air has been displaced.
D. Hydrogen needs to mix with air in order to form an explosive mixture.
E. None of the above.

6 and 7.  Reagent Shelf Question.  What two reagents did you use to prepare samples of hydrogen in the 60 cm³ syringe in the laboratory?
A.

B.

8.  Sketch the molecular orbital diagram for dihydrogen in the space below.  Which of the following is a correct statement about this MO diagram?  (The sketch must be shown for credit on this problem.)

A. The number of bonding MOs equals the number of antibonding MOs.
B. The molecular orbital utilizes p-bonding.
C. A similar MO diagram could be used for D2.
D. A similar MO diagram could be used for Li2.
E. More than one of the above.

9.  What is tritium?

A.  ²₁H

B. ¹₂H

C. ³₁H

D. ¹₃H

E. H3

10.  Which of the following is the formula of a reasonable metal hydride?
 

A. CaH
B. KH2
C. BeH3
D. LiAlH3
E. NaH
 

1.  D
2.  A
3.  A
4.  C
5.  D
6.  HCl +
7.  Mg
8.  E (A, C and D)
9.  C
10.  E