The Clandestine Lab: A Qualitative Analysis
Experiment
Hand-In, Chem 150L, Fall 2015
Name:
Partner:
1. (10 points) For each of the following ten combinations of reagents write a balanced net-ionic
equation assuming that 10 drops of the first reagent was combined with 5 drops of the second
reagent. Note that each equation will be worth 1 point. See the grading rubric below for more
details on the grading.
Guidelines for writing reactions:
a. If a solution became cloudy or gel-like or an obvious solid formed you should indicate that
one of the products is a solid with the physical state designator (s).
b. If a solution ONLY changed colors but remained clear, the product is not a solid but is a
soluble product. The formulas of these products are harder for you to predict at this point in the
year so you may simply show the reactants on the left side of the arrow and on the right side of
the arrow write “complex ion”.
c. If a reaction ONLY generates heat you can assume the reaction is an acid-base reaction. In
this case, the nature of the base will determine whether the product is H2O(l) or something else.
d. Read the notes on the second page of the lab procedure in your lab manual. If there was no
reaction for a particular combination you should write the reactants on the left side of the arrow
and on the right side of the arrow write No reaction.
e. It will be helpful for you to remember that a solution of the neutral weak base NH3 always has
some NH4+(aq) and OH–(aq) ions in it.
f. For some of the solutions the identity of the ion reacting will depend on what else it is reacting
with. For example, in HCl(aq), sometimes the H+(aq) ion may react and sometimes the Cl–(aq)
ion may react instead. Use everything you know about the compounds to help you write the
equations.
Grading Rubric for net-ionic equations
-5pts: Correct formulas and products, but no attempt to balance
-3pts: No state labels or very few state labels
-2pts: A couple major, obvious errors
-1pt: A few minor errors or inconsistencies
For numerous major errors or being incomplete more points may be taken off.
If you do not use subscripts and superscripts to properly format your chemical formulas and
equations, you will earn zero points for balancing your net ionic equations.
a.
10 drops Ni(NO3)2 and 5 drops NH3
{Write reaction here. You can copy and paste this arrow  . For each reaction remember to
write a net-ionic equation and to include charges and physical states as appropriate.}
b. 10 drops Pb(NO3)2 and 5 drops HCl
{Write reaction here and in the corresponding place for later reactions.}
c. 10 drops HNO3 and 5 drops Na2CO3
d. 10 drops CuSO4 and 5 drops NaOH
e. 10 drops Fe(NO3)3 and 5 drops HCl
f. 10 drops HCl and 5 drops AgC2H3O2
g. 10 drops Fe(NO3)3 and 5 drops NH3
h. 10 drops NH3 and 5 drops H2SO4
i. 10 drops of H2SO4 and 5 drops CaCl2
j. 10 drops NaI and 5 drops HNO3
2. (10 points) Identify the contents of each of your unknowns with a brief explanation.
Unknown
Identity
Explanation
letter and #
Y4
This acid generated heat when reacting with bases and formed
H3PO4
a precipitate with transition metal ions.
Grading Rubric for Unknown Identification
-0.5 point for each solution incorrectly identified
-0.5 point for each explanation that is not clear or not consistent with earlier equations
Unknown
letter and #
Identity
Explanation (Make your explanation as long as necessary to
be clear. The text should wrap automatically and make the
cell as large as it needs to be.)