EXAM 2 CHEM 1310 WS11 Key
Version #2
1. Sulfur dioxide reacts with chlorine to produce thionyl chloride (used as a drying agent for inorganic halides) and dichlorine oxide (used as a bleach for wood, pulp and textiles).
If 0.400 mol of Cl
2
reacts with excess SO
2
, how many moles of Cl
2
O are formed?
A. 0.800 mol
SO
2
( g ) + 2Cl
2
( g )

SOCl
2
( g ) + Cl
2
O( g )
B. 0.400 mol
C. 0.0500 mol
D. 0.100 mol
E.
0.200 mol
2. Iodine pentafluoride reacts slowly with glass and violently with water. Determine its molecular mass.
A.
221.90 amu
B. 259.89 amu
C. 653.52 amu
D. 202.90 amu
E. 145.90 amu
3. Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis).
Al( s ) + Br
2
( l )

Al
2
Br
6
( s ) [unbalanced]
How many moles of Al are needed to form 2.43 mol of Al
2
Br
6
?
A. 7.29 mol
B. 1.22 mol
C. 2.43 mol
D. 1.62 mol
E . 4.86 mol
4. Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na
2
SO
4
.
A. 1.244

10
23
O atoms
B. 2.409

10 24 O atoms
C.
4.976

10
23
O atoms
D. 2.915

10 24 O atoms
E. 1.166

10 25 O atoms
5. Iron (III) chloride hexahydrate is used as a coagulant for sewage and industrial wastes. What is its formula?
A. Fe(Cl·6H
2
O)
3
B. Fe
3
Cl·6H
2
O
C. FeCl
3
(H
2
O)
6
D.
FeCl
3
·6H
2
O
E. Fe
3
Cl(H
2
O)
6

6. Calcium fluoride, CaF
2
, is a source of fluorine and is used to fluoridate drinking water.
Calculate its molar mass.
A. 118.15 g/mol
B . 78.07 g/mol
C. 99.15 g/mol
D. 59.08 g/mol
E. 50.01 g/mol
7. Aluminum metal reacts with chlorine gas to form solid aluminum trichloride, AlCl
3
. What mass of chlorine gas is needed to react completely with 163 g of aluminum?
A. 214 g
B. 245 g
C. 321 g
D. 489 g
E.
643 g
8. Balance the following equation:
B
2
O
3
( s ) + HF( l )

BF
3
( g ) + H
2
O( l )
A. B
2
O
3
( s ) + 2HF( l )

2BF
3
( g ) + H
2
O( l )
B. B
2
O
3
( s ) + H
6
F
6
( l )

B
2
F
6
( g ) + H
6
O
3
( l )
C.
B
2
O
3
( s ) + 6HF( l )

2BF
D. B
2
O
3
( s ) + 3HF( l )

2BF
3
3
( g ) + 3H
2
O( l )
( g ) + 3H
2
O( l )
E. B
2
O
3
( s ) + 6HF( l )

2BF
3
( g ) + 6H
2
O( l )
9. What is the formula for magnesium sulfide?
A. MgS
2
B . MgS
C. Mg
2
S
D. Mg
2
S
3
E. MgSO
4
10. Aluminum oxide, Al
2
O
3
, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al
2
O
3
.
A. 2.377 mol
B. 2.146 mol
C.
0.4660 mol
D. 1.105 mol
E. 0.4207 mol
11. Lead (II) nitrate is a poisonous substance which has been used in the manufacture of special explosives and as a sensitizer in photography. Calculate the mass of lead in 139 g of Pb(NO
3
)
2
.
A. 107 g
B. 90.8 g
C. 83.4 g
D.
87.0 g
E. 62.6 g

12. Balance the following equation for the combustion of benzene:
C
6
H
6
( l ) + O
2
( g )

H
2
O( g ) + CO
2
( g )
A . 2C
6
H
6
( l ) + 15O
2
( g )

6H
2
O( g ) + 12CO
2
( g )
B. C
6
H
6
( l ) + 9O
2
( g )

6H
C. C
6
H
6
( l ) + 9O
2
( g )

3H
2
O( g ) + 6CO
2
( g )
2
O( g ) + 6CO
2
( g )
D. C
6
H
6
( l ) + 15O
2
( g )

3H
2
O( g ) + 6CO
2
( g )
E. 2C
6
H
6
( l ) + 9O
2
( g )

6H
2
O( g ) + 12CO
2
( g )
13. Which one of the following formulas of ionic compounds is the least likely to be correct?
A. NH
4
Cl
B. Ba(OH)
2
C. Na
2
SO
4
D. Cu(CN)
2
E . Ca
2
NO
3
14. Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride?
A. 43.3 g
B. 62.3 g
C . 107 g
D. 92.9 g
E. 74.5 g
15. What is the name of PCl
3
?
A. phosphorus chloride
B. phosphoric chloride
C.
phosphorus trichloride
D. trichlorophosphide
E. phosphorus trichlorate
16. Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O.
Determine its empirical formula.
A. HNO
B.
H
2
NO
2
C. HN
6
O
16
D. HN
16
O
7
E. H
2
NO
3