Is the glass half empty or half full? shown that a speaker's choice of frame can reflect their knowledge of the environment, and that listeners can be sensitive to this information. 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
Hammett acidity function is a much stronger acid. The value H = -12 for pure sulfuric acid must not be interpreted as pH = -12 (which would imply an impossibly high HO concentration of 10 mol/L in ideal solution). Instead it means that the acid species present (HSO) has a protonating ability equivalent to HO at a fictitious (ideal) concentration of 10 mol/L, as measured by its ability to protonate weak bases. Although the Hammett acidity function is the best known acidity function, other acidity functions have been developed by authors such as Arnett, Cox, Katrizky, Yates, and Stevens. On this scale, pure