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) +
HCl(aq)
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)
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 (in grams) 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 limestonecontaining 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?
Environmental Analytical Chemistry
You’ve been hired by a graduate student to run her analyses in a sediment series. These
sediments were sampled in 2000. 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