Measuring pH of Direct and Throughfall Rain

Key Terms

Acid = a substance that liberates hydrogen ions when in an aqueous solution.

Acid Rain = precipitation such as rain, snow, sleet, hail, or dew that measures less than 7 on the pH scale. 

Base = a substance that accepts hydrogen ions; proton acceptor

Calibrate = to adjust the graduations of an instrument that is to be used for measurement. 

Hydronium ion = H⁺; a positively charged particle composed of hydrogen; found in acidic solutions. 

Hydroxide ion = OH^-; a negatively charged particle composed of hydrogen and oxygen in a ratio of 1 to 1; found in basic solutions.  

Indicator = a substance or compound that is used to provide evidence for the presence or absence of a specific condition. 

Neutralization = a chemical reaction that occurs between an acid and a base.

Leaching = removing by a solution. 

pH = the symbol for hydrogen ion concentration; a measure of the relative acidity or basicity of a solution. 

pH scale = the graduation in measurement of the balance of hydronium and hydroxide ions in a substance or compound. 

pH meter = an electronic instrument that is calibrated to measure the pH of a substance or solution. 

Pollution = the addition of harmful waste matter by human industry or natural phenomenon. 

Precipitation = (1) water molecules that form in the Earth’s atmosphere as dew, rain, snow, or hail; (2) formation of insoluble complexes that settle out of solution. 

Sulfur dioxide = SO₂; a gaseous compound composed of sulfur and oxygen.

Sulfuric acid = H₂SO₄; a liquid acidic compound composed of hydrogen, sulfur, and oxygen. 

Throughfall = Precipitation that has been filtered by leaves and branches of trees and bushes.