Ch. 8 & 18  chemical reactions                       test     [50 points]                   Chem

 

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 (i.e. a choice may be used once, never, more than once) by using the appropriate letter(s) corresponding to the type of reaction; use the following choices:   [10 points]

A.  acid-base                           B.  combustion

C.  decomposition                   D.  double replacement

E.  precipitation                       F.  redox

G.  single replacement             H.  synthesis

 

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

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”.   [9 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

 

4.  Identify the atom in the molecule that is reduced / oxidized.  [6 points]

 

a.  C2H6  +  O2  à  CO2  +  H2O

 

            _____  is oxidized and  ____ is reduced in the above reaction.

 

 

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

 

_____  is oxidized and  ____ is reduced in the above reaction.

 

 

c.  N2  +  H2  à  NH3

 

            _____  is oxidized and  ____ is reduced in the above reaction.

 

 

5.  If a precipitate forms in the below reaction, then write the chemical formula of the precipitate; otherwise, write “no precipitate”.  [15 points]

 

a.  AgNO3  +  NaCl  à                      precipitate =

 

b.  Ca(NO3)2  +  Li3PO4  à                precipitate =

 

c.  LiCl  +  MgBr  à                          precipitate =

 

d.  K2SO4  +  Pb(NO3)2  à                 precipitate =

 

e.  HCl  +  KOH  à                           precipitate =