Environmental Chemistry U6220
Lab #1
Balancing Equations:
1.
Cu2S(s) + O2 (g)  Cu(s) +
2.
NaNO3 +
H2SO4(l)  Na2SO4(s) + HNO3 (g)
3.
AlCl3(s) +
H2O(l)  Al(OH)3(s) +
4.
KCl(aq) + HNO3 (aq) + O2 (aq)  KNO3 (aq) + Cl2 (g) + H2O(l)
5.
As2S3(s) + O2(g)  As4O6(s) + SO2(g)
6.
C4H10(g) + O2(g)  CO2 (g) + H2O(g)
7.
Ca10F2(PO4)6(s) + H2SO4(l)  HF(g) + Ca(H2PO4)2(s) + CaSO4(s)
SO2 (g)
HCl(aq)
Stoichiometry:
1. a) Given the balanced equation below, how many moles of oxygen are required to burn 3 moles of
propane?
C3H8(g) + 5O2(g)  3CO2 (g) + 4H2O(g)
1. b) How many moles of carbon dioxide does that produce? How many grams of carbon dioxide does
that produce?
2. First balance the equation below. If you begin with 2.56g of cobalt metal and excess hydrochloric
acid, what mass of cobalt (II) chloride will be obtained? What mass of hydrogen gas will be obtained?
Co(s) + HCl(aq)  CoCl2(aq) + H2(g)
3. Balance the following equation:
(NH4)2PtCl6(s)  Pt(s) + NH4Cl(s) + N2(g) + HCl(g)
If you heat 12.35g of (NH4)2PtCl6, what mass of platinum metal is expected? How many
grams of HCL will be obtained?
Limiting Reactants:
1. Balance the following reaction:
S8 + O2  SO2
If you are given 20.0g of S8 and 160g of O2, which reactant will be limiting? How much of the excess
reactant will remain unreacted?
2. Aspirin is produced by the following reaction:
C7H6O3(s) + C4H6O3(l)  C9H8O4(s) + CH3CO2H(aq)
salicylic acid
acetic anhydride
aspirin
If you mix 100 grams of each reactant, what is the maximum amount of aspirin that can be produced?
Chemical Analysis:
1. A sample of limestone and other soil materials is heated, and the limestone decomposes to give
calcium oxide and carbon dioxide. A 1.506g sample of limestone-containing material gives 0.711g of
CaO, in addition to gaseous CO2, after being heated at a high temperature. What is the weight percent
of CaCO3 in the original sample?
Bonding:
1. Indicate which are covalently bonded compounds and which are ionic compounds. For the
covalent compounds, are they polar or non-polar? Are there covalent bonds within ionic compounds?
a) NaCl
b) H2O
c) CaCl2
d) CaCO3
e) NH3
f) NH4Cl
g) H2
h) O2
i) NaPO4
Environmental Analytical Chemistry
You’ve been hired by a graduate student to run her analyses in a sediment series. You just ran a
calibration curve and the whole series of sediment samples. You need to transform all arsenic data
(raw data) into mass per mass of sample. And you also want to run look at normalize the data per mass
of aluminum (given in percentage) and per unit mass of organic carbon (also given in percentage).
1) Draw your calibration curve and calculate your calibration equation. Is this an acceptable
calibration curve?
2) Transform all your raw data in total mass of arsenic (micrograms, ug)
3) Transform all you arsenic data in mass per mass of sediment (ug/g)
4) Plot your vertical profile of arsenic in the sediment column (vs. depth – cm)
5) On separate graphs, plot the As/Al and As/Corg profiles.
6) If you know that the sediments have accumulated in this lake at an average rate of 0.7 cm per
yr (cm/yr), plot the As concentration vs. age of sediments.
7) What can you say about your data in terms of
a. total arsenic content,
b. normalized content (to Al and Corg). Why would we want to normalize the data in this
way?
c. Arsenic vs. age