Name: 
 

Practice Test 1B



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

Calculate the mass in grams of 8.35x1022 molecules of CBr4.
A)
0.139 g
B)
0.0217 g
C)
46.0 g
D)
7.21 g
 

 2. 

Two naturally occuring isotopes of an element have the following masses and abundances:

Isotope 1            54.00 amu         20.00%
Isotope 2            56.00 amu         80.00%

What is the average atomic mass of this element?
A)
55.20 amu
B)
55.60 amu
C)
54.80 amu
D)
55.80 amu
 

 3. 

A compound contains 40.0% C, 6.7% H, and 53.3% O, with a molar mass of 60.0 g.  What is the molecular formula for this compound?
A)
CH2O
B)
C2H4O2
C)
C2H4O
D)
C3H8O
 

 4. 

What is the formula for lithium nitrite?
A)
LiNO2
B)
LiNO3
C)
Li2NO2
D)
Li2NO3
 

 5. 

How many Celsius degrees are there between 32F and 320 K?
A)
43
B)
288
C)
32
D)
47
 

 6. 

If the formula for barium cerate is BaCeO3, what is the correct formula for ferric cerate?
A)
FeCeO3
B)
Fe3(CeO3)2
C)
Fe2(CeO3)3
D)
Fe3CeO3
 

 7. 

A compound of chromium and silicon contains 73.52% by mass chromium.  What is its empirical formula?
A)
Cr3Si
B)
Cr3Si2
C)
CrSi3
D)
Cr2Si3
 

 8. 

When 9.44 grams of calcium are heated in the air, 13.22 g of calcium oxide is formed.  The percent by mass of oxygen in this compound is
A)
28.6%
B)
71.4%
C)
13.2%
D)
40.0%
 

 9. 

Which of the following is the correct sequence of coefficients when the equation below is balanced:

___H3PO4  +  ___ MgCO3  mc009-1.jpg  ___ Mg3(PO4)2 + ___ CO2 + ___ H2O
A)
2, 3, 1, 3, 2
B)
2, 2, 1, 2, 3
C)
2, 3, 1, 3, 3
D)
3, 1, 3, 2, 3
 

 10. 

A student performs an experiment to determine the density of a sugar solution.  She obtains the following results:  1.79 g/mL, 1.81 g/mL, 1.80 g/mL, 1.81 g/mL.  If the actual value for the density of the sugar solution is 1.80 g/mL, which statement below best describes her results?
A)
Her results are preciese, but not accurate.
B)
Her results are accurate, but not preciese.
C)
Her results are both precise and accurate.
D)
Her results are neither preciese nor accurate.
 

 11. 

What is the length of the metal bar shown below to the correct number of significant digits:

mc011-1.jpg
A)
15 cm
B)
15.0 cm
C)
15.00 cm
D)
15.000 cm
 

 12. 

What species is represented by the following information?

p+ = 12      n° = 14      e- = 10
A)
Si4+
B)
Mg
C)
Si
D)
Mg2+
 

 13. 

Which of the compounds listed below are listed in order of alkyne, alkene and alkane:
A)
C3H6 ; C4H10 ; C2H2
B)
C7H12 ; C5H10 ; C12H26
C)
C6H14; C5H12 ; C4H8
D)
C2H4 ; C4H10 ; C5H12
 

 14. 

How many anions are there in 2.50 g of MgBr2?
A)
8.18x1021
B)
1.64x1022
C)
4.43x1025
D)
8.87x1025
 

Short Answer
 

 15. 

Balance the following equation:

____ C8H18O3  +  ____ O2  sa015-1.jpg   ____ CO2  +  ____ H2O
 



 
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