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 + "m" + "m" + "m" - "m"". Total alkalinity is measured by adding a strong acid until all the anions listed above are converted to uncharged species. The total alkalinity is not (much) affected by temperature, pressure, or pH, though the values of individual constituents are, mostly being conversions between HCO and CO. Drever further notes that in most natural waters, all anions except HCO and CO have low concentrations. Thus carbonate alkalinity, which is equal to "m" + 2"m" is also approximately equal to the total alkalinity. Alkalinity or A measures the ability of a solution to neutralize