CH221 - 11:00                   EXAM #1                                     Practice


CONSTANTS   

        Avogadro:      6.022  ´ 1023 /mole 

       

MAIN GROUP ELEMENTS


Select the best single answer for each question:

1.  Evaluate 1.2253 ´ 71.4  to the correct number of significant figures.

A) 87
B) 87.5    
C) 87.49
D) 87.486
E) 87.4864

2.  Evaluate 19.10 mL + 1.52 L to the correct number of significant figures.

  
A) 1.54 ´ 103 mL  
B) 1.5 ´ 103 mL  
C) 1539 mL
D) 1539.1 mL
E) 1539.10 mL 
    

3.  Which is the largest mass?

A) 100 g 
B) 100 ng  
C) 100 kg  
D) 100 mg
E) 100 mg
  

4.  How many cubic meters are there in 100 cubic millimeters?
         
A) 108  
B) 1011
C) 10-6 
D) 10-8
E) 10-7  
 


5.  Give the ratio neutrons/protons in

            

         
A) 1.13  
B) 1.54
C) 2.16
D) 1.20   
E) 1.00  

6.  Give the number of electrons in the ion 

         
A) 56 
B) 28
C) 71
D) 39  
E) 123

7.  The formula for potassium bromide is

A) KBr   
B) K2Br3   
C) KBr2
D) K2Br
E) K3Br2
  

8.  The charge on the metal ion in the ionic compound FeO is

A) +1
B) +2      
C)  -1  
D)  -2
E) +3
  

 9.  The formula for calcium phosphate is

A) CaPO4
B) Ca2(PO4)3 
C) Ca3(PO4)2       
D) Ca3P2O8 
E) Ca3P3O12 
   

10.  The total number of sodium ions in 2 moles of sodium carbonate is:

 
A) 3.58 ´ 1024  
B) 1.30 ´ 1024 
C) 1.64 ´ 1024
D) 6.02 ´ 1023 
E) 2.41 ´ 1024  
   

11.  In the mineral carnotite K2(UO2)3(VO4)2·3H2O what is the ratio of

A) 1.50 
B) 2.67
C) 1.33
D) 3.25  
E) 2.83   
 

12.  The formula for the compound iron(III) chloride hexahydrate is

A) FeCl3·6H2O      
B) Fe3Cl·6H2
C) FeCl3·7H2O
D) Fe3Cl·7H2O
E) Fe3Cl(H2O)6  
   

13.  The molecular weight of nitric acid is

 
A) 51
B) 63  
C) 47
D) 79
E) 35
 

14.  What volume of 1.25 M sulfuric acid must be added to water to preparet 2.00 L of a 0.440 M solution?

  
A) 478 mL
B) 532 mL
C) 650 mL
D) 704 mL
E) 886 mL
   

15.  The systematic name of the compound PCl5 is

   
A) phosphorus(V) chloride 
B) phosphorus trichloride
C) phosphorus pentachloride   
D) phosphorus(V) trichloride
E) phosphorus(V) pentachloride
   

16.  Two successive reactions A ® B and B ® C have yields of 36% and 72%, respectively.
The overall yield for conversion of A into C is:   

A) 43%
B) 26%     
C) 38% 
D) 52% 
E) 100%
  

17.  What mass of A (MW =74.60) yields 75.0 g of C (MW = 48.32) by the reaction

3 A   ®   2 B  + 5 C

A) 75.0 g 
B) 86.3 g
C) 94.6 g
D) 52.1 g
E) 69.5 g  
  

18.  What volume (mL) of a 0.125 M solution of K2Cr2O7 (MW = 294.21) contains 1.85 g of K2Cr2O7?

A) 50.3 mL  
B) 104 mL 
C) 42.2 mL
D) 81.5 mL
E) 75.0 mL  
  

19.  Find the empirical formula of a compound that contains 0.912 g of phosphorous and 0.706 g of oxygen in a 1.618 g sample. 

A) P3O2
B) P3O4  
C) P2O3  
D) P2O5 
E) PO2
  

20.  What mass of CO2 is produced when 6.0 g of C2H2 and 10.0 g of O2 react by

                                  2 C2H2 + 5 O2  ®  4 CO2 + 2 H2O

A) 12.4 g 
B) 21.5 g  
C) 13.2 g
D) 11.0 g   
E) 9.6 g