CH221 - 11:00                      FINAL EXAM-B                                Practice


DATA, CONSTANTS AND FORMULAS

CONSTANTS 
Avogadro    N = 6.022  1023 /mole
speed of light   c = 2.998 108 m s-1
mass electron  me = 9.109 10-31 kg
Planck   h = 6.626
10-34 J-s
Bohr   ao = 52.92 pm
Bohr  
eo = 2.179 10-18 J 
Rydberg   RH = 1.097 107 m-1
FORMULAS
light wave:   ln = c
photon energy:  E = hn

HYDROGEN-LIKE ATOMS
1/l = RH Z2(1/n12-1/n22)  
rn = ao n2/Z
En = - eo Z2/n2
CONVERSION FACTORS
1 J = 1 kg  m2 s-2
1 cal = 4.184 J
angstrom 1 = 10-10 m  
1 nm = 10-9 m
1 pm = 10-12 m

SOLUBLE IONIC COMPOUNDS

STANDARD HEATS OF FORMATION

 C2H5OH( g)    -235  kJ     
 C2H5OH(l )     -278  kJ
 CH3CHO( g)    -166  kJ
 CH3CHO(l )     -192  kJ
 CO( g)              -110  kJ
 CO2( g)            -394  kJ
 CO2(aq)   -413  kJ
 H2O( g          -242  kJ
 H2O(l            -286  kJ
 NH3( g)               -46  kJ
 NH3(aq)             -81 kJ
 NO2( g)                33 kJ

PERIODIC TABLE OF ELEMENTS

   


Select one answer for each question:

1.  A piece of iron is heated from 25C to 115C.  What is the temperature change of the iron in degrees Fahrenheit?

 
A) -50F
B) 194F 
C) -130F
D) 162F    
E) 50
 

2.   How many picometers are there in one angstrom ()?     

 
A) 1000
B) 100  
C) 10
D) 1
E) 0.1
    

3.  What is the concentration of KNO3 after 40.0 mL of water is added to 160.0 mL of 0.128 M KNO3?

 
A) 0.116 M  
B) 0.128 M
C) 0.102 M  
D) 0.092 M
E)   0.142 M
   

4.  What volume of 0.125 M barium hydroxide will exactly neutralize 200 mL of 0.160 M nitric acid?
         
A) 128 mL  
B) 64 mL
C) 256 mL
D) 96 mL
E) 192 mL
 


5.  The systematic name of the neutral compound ClO4 is:

         
A) chlorine(VIII) oxide
B) perchlorate
C) tetraoxygen chloride
D) chloric oxide
E)  chlorine tetraoxide  
 

6.  Give the sum of the coefficients when the combustion equation is balanced with lowest integers:

                         __C6H14  +  __ O2      __ CO2   +  __ H2O

 
A) 41
B) 57
C) 33
D) 47   
E)    39   
 

 7.  The total number of ions released when 1.62 moles of calcium chloride dissolve completely in water is:

 
A) 1.95 1024 
B) 4.88 1024  
C) 2.93 1024     
D) 3.21 1024 
E) 1.46 1024
 

 8.  Two successive chemical reactions A B and B C have yields of 25% and 64%, respectively.  The yield for the overall conversion of A C is:  

 
A) 39%
B) 16% 
C) 89%
D) 25% 
E) 21%
   

9.  Oxidation-reduction reactions involve transfer of   

    
A) electrons from the reducing agent to the oxidizing agent   
B) protons from the oxidizing agent to the reducing agent
C) electrons from the oxidizing agent to the reducing agent
D) protons from the reducing agent to the oxidizing agent
   

10.   What is the volume of 1.25 moles of aluminum carbide (density = 2.36 g/mL)?

 
A) 47.8 mL 
B) 76.3 mL   
C) 20.7 mL
D) 55.6 mL 
E)    69.9 mL     
 

11.  Give the moles of electrons exchanged in the balanced equation

                                As4S6  + 9O2    As4O6  +  6SO2

  This type of redox problem will not be on the CH221 final
A) 12
B) 0
C) 48
D) 36 
E) 24
 

12.  Find the oxidation number of nitrogen in a compound NxOy if 7.143 g of the compound contains 2.597 g of oxygen. 

         
A)
B) 4
C) 3
D) 2
E) 5
 

13.  Use the following reaction data

                       Fe2O3 + 3CO    2Fe + 3CO2  DH = -26.8 kJ

                              FeO + CO   Fe + CO2  ,    DH = -16.5 kJ

 to find the enthalpy change for the reaction

                      Fe2O3  + CO    2FeO  +  CO2

  
A) 27.7 kJ
B) 10.3 kJ
C)  6.2 kJ     
D) - 43.3 kJ
E) -10.3 kJ
      

14.  Which of these samples of ionic compounds releases the largest number of ions when placed in water?

 
A) 0.3 mole of Al(OH)3
B) 0.2 mole of NaCl    
C) 0.2 mole of PbBr2
D) 0.1 mole of (NH4)2CO
E) 0.4 mole of CaSO4
  

15.  How many moles of electrons can be transferred in a fuel cell based on the equation

                                        2H+  O2    2H2O 
 
 
with 12 g of hydrogen and 72 g of oxygen.  (HINT: this involves a limiting reactant.) 

 this type of redox problem will not be on the CH221 final
A) 18
B) 6
C) 15
D) 9  
E) 12
     

16.  Identify the oxidizing agent in the equation:

                      H3IO62- + HSnO2-  +  H2O    IO3-  +  Sn(OH) 62-

      
A) HSnO2-      
B)  Sn(OH) 62- 
C) H2O  
D)  IO3-
E) H3IO62-             
        

17.  Which mixture of solutions does not produce a solid precipitate?

 
A) potassium iodide and lead(II) nitrate 
B) silver(I) nitrate and sodium chloride
C) calcium nitrate and sodium sulfide   
D) copper(II) sulfate and ammonium carbonate  
E) sodium hydroxide and cobalt(II) chloride  
 

 18.  What is the wavelength of the electromagnetic radiation from a cell phone that operates at 8.50 108 s-1 ?

  
A) 35.3 cm  
B) 25.4 cm
C) 15.6 cm
D) 52.9 cm
E) 43.1 cm 
   

19.  What is the principal quantum number of the occupied orbital in the ground state of the hydrogen atom?

      
A) 2
B)
C) 0
D) -1
E) -2
   

20.  What is the angular momentum quantum number for a 3p orbital?

 
A) 1  
B) 3
C) 2
D) 0
E) 4
 

21.  According to ________ a particle of mass m and velocity v has a wavelength l = h/mv.   

 
A) Planck
B) Rydberg
C) Bohr
D) Einstein
E) de Broglie    
  

22.  The allowed values of ml when n = 3 and l = 2 in the hydrogen atom are:

         
A) 0, 1, 2, 3
B) 3, 2, 1, 0, -1, -2, -3
C) 0, 1, 2
D) 2, 1, 0, -1, -2   
E) 1, 0, -1
 

23.   Which of these shapes are consistent with atomic orbitals that have n = 2?

   
1) 2) 3) 4) 5)
   
A) 3, 5  
B) 1, 2, 4
C) 1, 3, 5
D) 2, 3, 4, 5
E) 1, 5
   

 
24.  What is the radius of a  hydrogen-like ion F8+ with n = 2 in the Bohr model? 

  
A) 30.2 pm
B) 23.5 pm   
C) 34.6 pm
D) 18.7 pm   
E) 26.5 pm
 

25.  Which of these transitions in the hydrogen atom emits radiation at the longest wavelength?

 
A) 4 3
B) 2 1
C) 5 4  
D) 3 2
E) 100 1 
     

26.  Which atom has the electron configuration 1s2 2s2 2p6 3s2 3p2 ?

 
A) oxygen
B) aluminum
C) sulfur
D) phosphorus
E) silicon   
 

27.   The maximum number of 4d electrons is: 

 
A) 12
B) 18
C) 14
D) 10  
E) 16
 

 28.  What is the highest value of n in the electron configuration for Pb?

 
A) 6  
B) 3
C) 7
D) 5
E) 4
  

29.  How many p electrons are there in Br?

       
A) 18
B) 16
C) 17   
D) 21
E) 15
   

30.   In which atom does the electron configuration in the highest unfilled subshell look like this?

A) Si
B) S
C) Sc
D) Sn
E) Sb 
     

 31.  What is the energy of one mole of photons whose wavelength is 319 nm?

 
A) 288 kJ
B) 375 kJ   
C) 623 kJ
D) 324 kJ
E) 415 kJ
 

32.   What mass of oxygen is consumed in the combustion of 63.4 g of acetaldehyde by the equation

                              2CH3CHO(l) + 5O2(g)    4CO2(g) + 4H2O(l)

 
A) 110 g 
B) 57.6 g 
C) 233 g
D) 115 g
E) 221 g
   

33.   How much heat is produced in the preceding Question 32?

 
A) 1609 kJ
B) 1736 kJ 
C) 1681 kJ    
D) 1592 kJ
E) 1719 kJ