Classroom Activity
Rainwater Analysis for the Presence of Ions

Identify the problem:  The purpose of this laboratory experience is to investigate the difference between the presence of ions in rain that falls directly on the ground to rain falls through tree branches.  The information in the data table that is included with this activity is actual research data that was collected from Waites Island, South Carolina.  It is important to note:  there were several weeks of no rain before samples were collected on June 18th.  Please remember this when analyzing the data.   

Gather information:  Research acid rain (its causes and composition), ions and polyatomic ions, and all key terms provided with this lab.  Utilize the data table provided:  RAINWATER ANALYSIS FOR PRESENCE OF IONS (ppm).  The measurement of ions in ppm (parts per million) found in each sample of rainwater is listed, along with the actual months or dates that water samples were collected.   

Organize the data:  Construct one graph for each ion comparing the monthly samples of the direct rainfall with the monthly samples of the throughfall rain.  Then construct one graph each ion, comparing the event samples of the direct rainfall with the event samples of the throughfall rain.  You will make a total of ten graphs.   

Form conclusions:  On the pages following the data table you will find the Comparison of Ions Detected section, write complete sentences to explain your analysis of the graphed data.

Evaluation:   Submit your graphs along with your Comparisons of Ions Detected explanations to the teacher for grading with an unmarked, clean copy of the rubric attached to the top.

 

 

 

 

 

RAINWATER ANALYSIS FOR PRESENCE OF IONS (ppm)
Direct Rainfall vs. Throughfall Rain
Monthly and Event Samples

 Direct Rainfall – Monthly

                        F-                      Cl-                    NO2-                NO3-                SO42-

 March         0.05                 1.75                 0.01                 0.19                 1.16
April              0.04                 4.37                 0.01                 0.21                 1.78
May              0.05                 1.65                 0.01                 0.22                 1.51
June             0.06                 1.69                 0.01                 0.22                 1.51
July               0.06                 1.68                 0.01                 0.12                 0.93

 

Direct Rainfall – Event

                            F-                      Cl-                    NO2-                NO3-                SO42-

 June 18       0.13                 1.25                 0.01                 0.11                 0.72
June 20        0.04                 1.76                 0.01                 0.15                 1.29
June 21        0.00                 1.45                 0.01                 0.06                 0.82
June 22        0.04                 2.23                 0.01                 0.11                 0.74
July 5             0.12                 3.99                 0.01                 0.74                 3.38

 

Throughfall  Rain – Monthly

                        F-                      Cl-                    NO2-                NO3-                SO42-

 March         0.04                 13.66              0.00                 0.25                 4.32
April              0.04                 16.25               0.00                 0.60                 4.95
May               0.04                 11.79               0.01                 0.39                 4.34
June              0.04                   6.63               0.01                 0.39                 2.89
July                0.04                   5.48              0.01                 0.41                 2.72

 

Throughfall Rain – Event

                          F-                      Cl-                    NO2-                NO3-                SO42-

 June 18      0.05                 6.95                 0.01                 0.75                 2.76
June 20       0.04                 2.59                 0.01                 0.10                 1.46
June 21       0.04                 3.38                 0.01                 0.06                 1.36
June 22       0.00                 1.57                 0.01                 0.04                 0.66
July 5            0.00                 1.55                 0.01                 0.04                 0.66

 

Student name ______________________

 

Comparison of Ions Detected:  Direct Rain vs. Throughfall

 

Fluoride

1.  a.  Looking at the graph constructed for the presence of fluoride ions in the monthly samples of direct and throughfall rain, explain any differences that can be observed. 

 

 

     b.  Explain any evidence for the occurrence of deposition in the throughfall samples. 

 

 

c.      Explain any evidence that leaching may have occurred.   

 

 

2.  a.  Looking at the graph constructed for the presence of fluoride ions in the event samples of direct and throughfall rain, explain any differences than can be observed.     

 

 

     b.  Explain any evidence for the occurrence of deposition in the throughfall samples. 

 

 

     c.  Explain any evidence that leaching may have occurred. 

 

 

Chloride

1.  a.  Looking at the graph constructed for the presence of chloride ions in the monthly samples of direct and through fall rain, explain any differences that can be observed.   

 

 

     b.  State two explanations relating to data collection and analysis for the increase in chloride ions in the April water sample.   

 

 

     c.  Explain any evidence for the occurrence of deposition in the throughfall samples. 

 

 

     d.  Explain any evidence that leaching may have occurred. 

 

 

2.  a.  Looking at the graph constructed for the presence of chloride ions in the event samples of direct and throughfall rain, explain any differences that can be observed.   

 

 

b.      Explain any evidence for the occurrence of deposition in the throughfall samples.

 

 

c.      Explain any evidence that leaching may have occurred.   

 

 

d.  Consider wind patterns on the eastern coastline of South Carolina in June and July (hurricane season).  What could be a possible reason for an increase in presence of chloride ions in the direct rainfall event samples during these months?   

 

Nitrite

1.  a.  Looking at the graph constructed for the presence of nitrite ions in the monthly samples of direct and throughfall rain, explain any differences that can be observed. 

 

 

     b.  Explain any evidence for the occurrence of deposition in the throughfall samples.

 

 

     c.  Explain any evidence that leaching may have occurred.

 

 

2.  a.  Looking at the graph constructed for the presence of nitrite ions in the event samples of direct and throughfall rain, explain any differences that can be observed. 

 

 

b.      Explain any evidence for the occurrence of deposition in the throughfall samples.

 

 

c.      Explain any evidence that leaching may have occurred. 

 

Nitrate

1.  a.  Looking at the graph constructed for the presence of nitrate ions in the monthly samples of direct and throughfall rain, explain any differences that can be observed.   

 

 

     b.  Explain any evidence for the occurrence of deposition in the throughfall samples. 

 

 

     c.  Explain any evidence that leaching may have occurred. 

 

 

2.  a.  Looking at the graph constructed for the presence of nitrate ions in the event samples of direct and throughfall rain, explain any differences that can be observed.   

 

 

b.      Explain any evidence for the occurrence of deposition in the throughfall samples. 

 

 

c.      Explain any evidence that leaching may have occurred. 

 

Sulfate

1.  a.  Looking at the graph constructed for the presence of sulfate ions in the monthly samples of direct and throughfall rain, explain any differences that can be observed. 

 

 

     b.  Explain any evidence for the occurrence of deposition in the throughfall samples. 

 

 

     c.  Explain any evidence that leaching may have occurred. 

 

 

2.  a.  Looking at the graph constructed for the presence of sulfate ions in the event samples of direct and throughfall rain, explain any differences that can be observed.   

 

 

b.      Explain any evidence for the occurrence of deposition in the throughfall samples. 

 

 

c.      Explain any evidence that leaching may have occurred.