Is the glass half empty or half full? Is the glass half empty or half full? "Is the glass half empty or half full?" is a common expression, a proverbial phrase, generally used rhetorically to indicate that a particular situation could be a cause for optimism (half full) or pessimism (half empty), or as a general litmus test to simply determine an individual's worldview. The purpose of the question is to demonstrate that the situation may be seen in different ways depending on one's point of view and that there may be opportunity in the situation as well as trouble. Another perspective comes from psychology, where research has
Alkalinity mining has contributed to increased alkalinity concentrations in some major rivers throughout the Eastern U.S. The following reaction shows how acid rain, containing sulfuric acid, can have the effect of increasing river alkalinity by increasing the amount of bicarbonate ion: Another way of writing this is: The lower the pH, the higher the concentration of bicarbonate will be. This shows how a lower pH can lead to higher alkalinity if the amount of bicarbonate produced is greater than the amount of H remaining after the reaction. This is the case since the amount of acid in the rainwater is low.