Consider a diprotic acid with pKa values of 1.60 and 4.50, that is colorless when fully protonated, deep blue when singly deprotonated, and bright red when doubly deprotonated. Assuming that both colored forms have large and approximately equal molar absorptivities, what can be inferred from a solution of the compound that has a faint blue color

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.

the answer is 2-methylbutane. i just took a quiz and i got it wrong and this is what my teacher sai the correct answer was.