Ch. 8 & 18  chemical reactions                       test     [60 points]                   honors Chem

 

For problems involving calculations, show your work in an organized manner, include any relevant equation (or formula and conversion factor(s)), put the proper units in your calculations / answer, and have the proper number of significant figures in your answer.              

 

Academic Honesty:   The answers on this test are my own and I am using only the allowed set of notes as described in the syllabus.  I have not discussed the test questions with anyone before or during the test nor have I seen the test questions prior to the exam.  If you violate any of the preceding items or do not sign, your semester grade is a F.

 

                                                                                                Signature:  ___________________

 

1.  Indentify the type(s) of reactions; use the following choices:   [10 points]

 

a.  AgNO3  +  Sn  à  Sn(NO3)2  +  Ag                      Rx type(s)  =

 

b.  HNO3  +  NaOH  à  H2O  +  NaNO3                  Rx type(s)  =

 

c.  CH3OH  +  O2  à  CO2  +  H2O                            Rx type(s) =   

 

d.  O2  +  H2  à  H2O                                                 Rx type(s) =

 

e.  CH3NH2  à  C  +  H2  +  N2                                 Rx type(s) =

 

2.  What is the oxidation number of  __.  [10 points]

a.  carbon in carbon tetrachloride

b.  Cr in Na2Cr2O7

c.  S in sulfate

d.  phosphorus in phosphate

e.  Fe in Fe(NO3)2

 

3.  Write the net ionic equation.  Need not write a balanced chemical equation, but the chemical formula has to be correct; if there is no reaction, then write “no reaction”.   [15 points]

 

a.  mix aqueous solutions of sodium bicarbonate and nitric acid (i.e. hydrogen nitrate)

 

b.  add copper metal to a solution of hydrochloric acid

 

c.  mix aqueous solutions of calcium nitrate and potassium carbonate

 

d.  the combustion of methane, CH4

 

e.  mix aqueous solutions of barium chloride and lithium iodide

 

 

4.  Identify the species that is oxidized and species that is reduced in the following reactions.  [10 points]

 

a.  C2H6  +  O2  à  CO2  +  H2O

 

b.  (hydrogen peroxide)  H2O2  à  H2O  +  O2

 

c.  Zn(NO3)2  +  Cu  à  Cu(NO3)2  +  Zn

 

d.  N2  +  H2  à  NH3

 

e.  HI  +  Cl2  à  I2  +  HCl

 

5.   An unknown sample contains only 1 of the below chemicals:

 

BaCl2                           Na2CO3

Ba(OH)2                      NaI

                                    NaOH

                                                Na2 SO4

 

Based on the following sequential experimental observations, what is / are the possible compound(s) in the sample (after each sequential observation) ?  The addition of  ___ to the sample  ___.     [15 points]

 

a.  K2 SO4 . . . does not produce a precipitate

 

b.  Zn(NO3)2 . . . produces a precipitate

 

c.  CaCl2   . . . does not produce a precipitate.