Homework #1 (updated 1/14/07)

 

Modified from Fetter, Chapter 1:

 

1. How many grams of  KCl is in one liter of a 0.1-molar solution?

 

2. How many ppm of Na+ and Cl- are in a 0.23 mM solution?  (assume ppm = mg/L)

 

 

Modified from Appelo and Postma, Problem 1.1:

 

3. An analysis of groundwater gave as results (in mg/l):

 

pH

Na+

K+

Mg2+

Ca2+

Cl-

Alk

SO42-

mg/l

8.5

62

0.1

9

81

168

183

--

 

(Alkalinity is expressed as mg/l HCO3-.)

 

Build a simple spreadsheet (keeping one sample on one row) to convert these concentrations to:

  1. Convert to molal concentrations.
  2. Convert results into meq/L.
  3. Calculate charge balance.  Is the analysis charge balanced?
  4. Input the sample into Web PhreeqC.  How does the charge balance compare?

 

From Kehew, Problem 5 Chapter 1:

4. The following ground water analyses are expressed in mg/l. 

a) Plot Stiff and Piper graphs for each analysis. 

b) Use your spreadsheet to calculate the charge balance error for each analysis and state its chemical facies (analyses from Hem, 1989).

  Ca2+ Mg2+ Na+ K+ Alk SO42- Cl- NO3- Fe pH
1. 48 3.6 2.1   152 3.2 8.0   0.05 7.5
2. 144 55 29   622 60 53 0.3    
3. 394 93 333   157 1150 538 5    
4. 40 22 0.4 1.2 213 4.9 2.0 4.8 0.24 7.4
5. 140 43 21   241 303 38 4.1 0.01 7.4
6.* 3.0 7.4 857 2.4 2080 1.6 71 0.2 0.15 8.3
7.** 40 50 699 16 456 1320 17 1.9 0.4 8.2
8. 353 149 1220 9.8 355 1000 1980 24 0.01  

*CO3= = 57  **CO3= = 26