Answers to UNIT 6 Self Test:

1.    (a) Since this compound is on the left side of the arrow it is a reactant.

2.    (c) decomposition since single reactant breaks down into two products

3.    (a)

4.    (a) CaI2 because Ca is +2 and I is -1.

5.    (a) metal must be above metal ion on the activity series for a reaction to occur.

6.    (d) Ag is lowest on the activity series therefore its ion would be replaced by all the others.

7.    (a) since Ca is higher than Cu on the activity series

8.    (d) both (c) and (b) are correct interpretations of a balanced chemical equation

9.  (d) 2.5 mol *[2 mol/1mol] = 5.0 mol

10.  (c) 1 mol *[8 mol/2 mol] = 4 mol

11.  (c) 13 L *[2 L/1 L] = 26 L

12.  (a) Since 2.0 mol Zn requires only 4.0 mol HCl

Part 2 Problems (see board in class for work)

  1. Balance the following equations.  Tell what type of reaction each represents.

a.         Zn     +     2 HCl    à   H2(g)  +   ZnCl2  single replacement

b.         3AgNO3   +   AlI3   à   3AgI(s)   +   Al(NO3)3  double replacement

c.         2 Al2O3  à   4 Al   +   3 O2(g)  decomposition

d.         2 C4H10   +   13 O2   à   8 CO2(g)   +  10 H2O(g)  combustion

e.         2 Fe   +   3 Br2   à   2 FeBr3  direct combination

f.          Na2SO3   +   H2SO4   à   Na2SO4   +   H2O   +   SO2(g)  double replacement (and decomposition)

  1. Complete and balance the following equation.  What must be true of one of the products?

2 Li3PO4   +  3 Zn(NO3)2   à  6 LiNO3(aq)  +  Zn3(PO4)2 (s)  one of the precipitate

  1. Balance the following equations.

(a)        FeCl3(aq)   +    3 NaOH(aq)   à    Fe(OH)3(s)   +  3 NaCl(aq)

(b)        2 HCl(aq)  +     CaCO3(aq)   à    CaCl2(aq)   +   H2O(l)   +     CO2(g)

(c)        Al2O3(s)  +   3 H2O(l)  à    2 Al(OH)3(s)

  1. Complete the following equations and balance them.

(a)       2 C6H14(g)  +    19 O2(g)  à  12 CO2 + 14 H2O

(b)        2 NCl3(s)  à  N2  +  3 H2

(c)        3 Zn(s)  +      2 FeCl3(aq)   à  3 ZnCl2  +  2 Fe
                     (reaction does occur)

5.   (a) 12.2 L   (b)  75.0 g         6.  2.06 x 1023 molecules    7. 378 g Al2O3     8.  Aluminum