Ch. 8 & 18 aqueous reactions                          test     [80 points]                   honors Chem

1. Use the following hypothetical experimental data and the below graph to estimate the concentration of vit C (in mg / mL) of a fruit.  [10 points]

[vit C]  (mg / mL)

# drops of I2

0

1

0.125

4

0.25

8

0.50

16

1.0

31

Fruit

20


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

a. Mn in KMnO4 is  ______

b.  Sulfur in the sulfate ion is ____

c.  C in CH3OH is ___

d.  Nitrogen in nitrogen gas is  ____

e.  Nitrogen in barium nitrate is  ____

3.  Identify the atom (in the molecule) that are involved in oxidation and reduction (in the both the reactant and product) in the following redox reactions; include the oxidation number near the atom that is oxidized or reduced.  [12 points]

a. CH3OH   +   O2   →   CO2   +   H2O

Oxidized:  _______________________

Reduced:  _______________________

  b. Zn  +  H +  →  H2O  +  Mn 2+  +  Zn 2+

Oxidized:  _______________________

Reduced:  _______________________

4. Write the net ionic equation for the following reactants; if there is no reaction, then write “no reaction”.    [15 points]

a.  mix aqueous solutions of calcium nitrate and potassium phosphate

b. mix aqueous solutions of sodium carbonate and lithium hydroxide

c.  add solid zinc into an aqueous solution of hydrogen chloride

d.  the combustion of CH4

e. mix aqueous solutions of sodium sulfate and barium nitrate


5. Identify the type(s) of reactions using the below list of possible reactions.   [10 points]

double replacement reaction                            single replacement reaction
combustion reaction                                        redox reaction
acid / base reaction                                          synthesis reaction
precipitation reaction                                       decomposition reaction

a. C6H12O6  +  O2  →  CO2  +  H2O is  ______________________________

b.  Cu  +  HNO3  →  Cu(NO3)2  +  NO2  +  H2O is  _____________________

c.  Zn  +  HBr  →  ZnBr2  +  H2  is  _________________________________

d.  mixing aqueous solution of hydrogen nitrate and potassium hydroxide is  _______________________

e.  mixing aqueous solutions of magnesium nitrate and sodium carbonate is ________________________

6. Describe an experimental protocol, based on solubility rules, to differentiate between an aqueous solution of __; include an interpretation of your observations.   That is, add ___, where there’s a precipitate in one case and no precipitate in the other case.   Choices to fill-in the 2nd blank:  NaOH, Na3PO4, Na2CO3, NaI, Na2SO4, AgNO3, Pb(NO3)2, Co(NO3)2, Cu(NO3)2, Ba(NO3)2, Fe(NO3)2, Mg(NO3)2; there may be more than one correct answer to fill-in the 2nd blank.  [20 points]