Lycoming College                                                                                                   Write name on back,

Chem 110, 2002                                                Exam I                                                        upper right

 

 

 

1.   Matching:  match the items in the right column by writing in the CAPITAL letter of a selection from the items in the left. 

 

      A.  Dalton                                                              _____  6.022 x 1023

 

      B.   Petrucci                                                            _____  10B,  11B

 

      C.   nano                                                                 _____  RNHR

 

      D.  Avogadro                                                          _____  10-6 

 

      E.   Rutherford                                                        _____  M

 

      F.   ether                                                                 _____  ROH

 

      G.   alcohol                                                              _____  10-9

 

      H.  2° amine                                                           _____  nuclear atom

 

      I.    moles solute per liter solution                              _____  Hill

 

      J.    isotopes                                                            _____  ROR

 

      H.  micro                                                                _____   atomic theory                                      

 

 

 

2.   Two atoms are 154 pm apart.  Express this distance in cm, using scientific notation.

 

 

 

 

 

 

 

3.   a.   Determine the molar mass of (NH4)2SO4 to five significant figures.  Include with your answer the units for molar mass.

 

 

      b.   Name (NH4)2SO4 __________________________________________

     

      c.   How many individual atoms of H are there in 4.32 g of (NH4)2SO4?

 

 

 

 

 

 

           

 


 

4.   Complete the following table.  In the first row, E stands for an element you need to identify.  On the second row, write the complete symbol for the species.

 

Symbol

# protons

# neutrons

# electrons

net charge

Name of element

 

 

 

 

+2

 

 

 

16

 

16

 

18

 

 

 

 

 

5.   A bottle contains 500.0 mL of ketchup (catsup for some of us).  The density of ketchup is 1.4 g/mL.  What is the mass of the ketchup in the bottle, in kg?  Express answer with the correct number of significant figures and units.       

 

 

 

 

 

 

 

 

 

 

 

                      

 

6.   Name the following compounds, or provide the correct formula (structural formula where necessary).

 

 

      a.   chromium(III) sulfite_______________________________________

 

 

      b.   sodium sulfide _______________________________________

 

 

      c.   perchloric acid _____________________________________________

 

 

      d.   hexyl propanoate  _______________________________________

 

 

e.       nonane _______________________________________

 

 

f.        CH3CH2CH2CH2COOH ________________________________________

 

 

g.       AuCl4____________________________________

 

 

h.       Mg(NO3)2 _______________________________________________

 

 


 

7.   Balance the following reaction equations:

 

a.         ____ Ca3(PO4)2      +      ____ H2SO4              ____ CaSO4       +      ____ H3PO4

 

 

 

b.         ____ C4H10         +        ____ O2                          ____ CO2         +     ____ H2O      

 

 

 

8.   How many grams of CuCl2.2H2O  (F.W. = 170.48) are needed to prepare 250 mL of 4.0 M CuCl2 solution?

 

 

 

 

 

 

 

 

9.   If 20 mL of 18 M H2SO4 is diluted with water to a final volume of 0.500 L, what is the resulting molarity of the H2SO4?

     

 

 

 

 

 

10.  An ionic compound is analyzed to contain, by weight, 30.34% calcium (Ca), 21.21% nitrogen (N), and 48.45% oxygen.  Deduce the empirical (simplest) formula of the compound.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11.  Write the molecular formula and give the name for the compound represented by the following “stick figure:”

 

      Formula__________________  Name ________________________________

 

 

 

12.  A carbohydrate having a molar mass of 360 g/mol is analyzed to have the empirical formula CH2O.  What is the molecular formula of this compound?

 

 

 

 

 

 

 

 

13.  The following equation represents a way of making beryllium nitride:

 

                                                3 Be(OH)2    +   2 NH3        6 H2O   +     Be3N2

 

      a.   How many grams of Be(OH)2  (F.W. = 43.03) would be needed in order to produce  125 g of Be3N2?

 

 

 

 

 

 

 

 

 

 

 

b.       If, in an attempt to run this reaction as described in part (a), 120 g of Be3N2 was actually collected, what was the percent yield of the reaction?

 

 

 

 

 

 

 

 

 

 

 

      c.   In a completely different experiment to run the reaction above, 50.0 g of Be(OH)2  and 50.0 g of NH3  mixed.  What is the maximum yield of Be3N2, in grams, that can be synthesized, assuming 100% yield?