Acid rain calculation

Unpolluted rain water has a pH of about 5.5. Acid rain has been shown to have a pH as low as 3.0. Calculate the [H+] ratio of acid rain to unpolluted rain. 

Atmospheric emissions of sulphur dioxide are either measured or estimated at their source and are thus calculated on a provincial or state basis for both Canada and the United States (Figure 2). While much research and debate continues, computer-based simulation models can use this emission information to provide reasonable estimates of how sulphur dioxide and sulphate (the final oxidized form of sulphur dioxide) are transported, transformed, and deposited via atmospheric air masses to selected regions. Such "source-receptor" models are of varying complexity but all are evaluated on their ability to reproduce the measured pattern of sulphate deposition over a network of acid rain monitoring stations across United States and Canada. In a joint effort of the U.S. Environmental Protection Agency and the Canadian Atmospheric Environment Service, eleven linear-chemistry atmospheric models of sulphur deposition were evaluated using data from 1980. It was found that on an annual basis, all but three models were able to simulate the observed deposition patterns within the uncertainty limits of the observations (22). 

The most acid rain on record had pH — 2.00. Calculate the concentration of Ca - - cations in a solution formed when this rain becomes saturated with calcium carbonate. 

The ratios of relative concentration can not be calculated because the heavy metal contents of rice or vegetables growing in an acidic rain area or in a non-acidic rain area is lower than the method detection limit (MDL) of heavy metals. 

Acid rain is a matter of serious concern because most species of fish die in waters having a pH lower than 4.5-5.0. Calculate the H30 + concentration in a lake that has a pH of 4.5. 

We have employed two multi-elemental techniques (INAA and ICP-AES) to determine sulphur, halogens and 14 other trace elements in urban summer rainfall. Quality control was assured using NBS reference materials. The overall accuracy and precision of these two methods makes possible the routine analysis of many environmentally important trace elements in acid rain related investigations. Enrichment factor calculations showed that several elements including S, Cu, Zn and Cr were abnormally enriched in the urban atmosphere. A comparison of three separate sites showed a strong gradient of metal deposition from the industrial to the outlaying areas. 

Sulfur dioxide in the atmosphere contributes to acid rain. One method of controlling sulfur dioxide emission is to absorb the sulfur dioxide into a solution of a base. Calculate the mass of SO2 that can be absorbed by 125 kg of Ca(OH)2 to make CaS03. 

Neutralizing 5.00 L of an acid rain sample required 11.3 mL of 0.0102 M KOH. Calculate the hydronium ion concentration in the rain sample. 

Acid rain has been defined as any precipitation with a pH lower than 5.6. Why 5.6 instead of 7.0 Can you perform a calculation to reproduce this value ... 

Using a computer model developed from solution equilibrium techniques discussed by Lindsay [4], analytical data were used to calculate the activities and molarities of 29 species in solutions recovered from the coquina columns. A typical computer print-out shown in Figure 1 lists the solution species as well as their activities and molarities. The resulting data were used to interpret the effects of initial pH, ionic strength, acid rain composition and column length on degradation of coquina. 

To illustrate the effect of ionic strength on degradation of calcium carbonate we have calculated the solubility of calcium carbonate in deionized water, acid at pH = 4.0 and acid rain at pH = 4.0 with an ionic strength of 7.2 x 10 in the absence of CO2. The results of these calculations are shown in Table 2 and are plotted in Figure 3. These data show that the ionic strength contribution of sea spray and other atmospheric sources are as significant as the neutralization reaction with acid at pH = 4.0 in the degradation of coquina by acid rainfall. 

Figure 3. Plot of log total calcium vs ionic strength. Solid line, calculated solubility of calcium carbonate in equilibrium with atmospheric CO2. Calculated solubility of calcium carbonate in the absence of atmospheric CO2 for Circle, deionized water triangle, acid solution at pH = 4.0 star, acid rain at pH = 4.0.

Under Title IV, facilities must document and report annually regarding the aggregate amount of acid-rain precursors in the form of SO2 and NOx Determination of these amounts are traditionally handled by stack testing, with the emissions factor subsequently calculated in units of pound of species emissions per pound of fuel combusted, per hour of operation, or other. Title IV thresholds are subject to penalty when exceeded. Additionally, in the case of violation, the ERA can enforce a mandatory emissions reduction in the subsequent year to offset the excess emission value. 

Calculate the molecular masses of the following compounds (a) sulfur dioxide (SO2), which is mainly responsible for acid rain (b) ascorbic acid, or vitamin C (CeHgOe). 

Modern studies have already documented the occurrence of acid rains over Northern Thailand due to the increase in use of lignite as an energy source. Based on the critical load concept, Kozlov Towprayoon (1998) have shown that the critical load values of sulfur for terrestrial Tropical Rain Forest ecosystems of the region are rather low (less than 500eq/ha/yr). As a result of both the high SO2 emission rate and high sensitivity of ecosystems, the excessive input of acidity was calculated for more than 75% of the area considered (see also Chapter 15). 

Calculate the molar mass of sulfur dioxide, a gas produced when sulfur-containing fuels are burned. Unless "scrubbed" from the exhaust, sulfur dioxide can react with moisture in the atmosphere to produce acid rain. 

The idealized calculation just presented shows what are thought to be the essential elements of the aqueous-phase chemistry of acid rain. Measurements of H2O2 in rain and cloudwater show a range of concentrations between approximately 10 and 1(X) /itM (Kok, 1980 Zika et al., 1982). Water with this composition is in equilibrium with between 0.1 and 1.0 ppb gas-phase H2O2. Kleinman (1984) has examined the question of whether H2O2 can account for the in-cloud oxidation of SO2 and found that under summertime conditions between 3 and 5 ppb of H2O2 would be required to account for estimated incloud sulfate formation. Seigneur et al. (1984) presented the results of simulations of atmospheric sulfate and nitrate formation by both gas- and aqueous-phase paths under... 

From an environmental standpoint, the recognition that acid rain mobilizes aluminium from poorly buffered soils into the aquatic environment has increased the awareness and concern about aluminium toxicity to aquatic organisms. The acidification of fresh water lakes and rivers in the USA, Canada and particularly the Scandinavian countries, and the subsequent rise in dissolved aluminium levels, has been linked to the decline in fish numbers and, in some cases, to the total elimination of entire fish populations [159,160]. In aquatic systems, it has been demonstrated that the A1(0H)2 species seems to be most toxic to fish [159]. Other workers [161], using thermodynamic calculations in conjunction with fish toxicological experiments, have pointed to the Al(OH) species as also toxic to fish. 

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