Litmus test (politics) Litmus test (politics) A litmus test is a question asked of a potential candidate for high office, the answer to which would determine whether the nominating official would proceed with the appointment or nomination. The expression is a metaphor based on the litmus test in chemistry, in which one is able to test the general acidity of a substance, but not its exact pH. Those who must approve a nominee, such as a justice of the Supreme Court of the United States, may also be said to apply a litmus test to determine whether the nominee will receive their vote.
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