What is the ph of a 0.21 m solution of pyridinium chloride (c5h5nh+cl−)? (kb for pyridine is 1.5 × 10−9 .) answer in units of ph?

Which statement best describes the oxidation numbers of the atoms found in magnesium chloride? a. magnesium has a 2- oxidation number and chlorine has a 1+ oxidation number. b. magnesium has a 2- oxidation number and chlorine has a 2+ oxidation number. c. magnesium has a 2+ oxidation number and chlorine has a 1- oxidation number. d. magnesium has a 1+ oxidation number and chlorine has a 1- oxidation number.

Acompound has a molecular weight of 12.124 atomic mass units and the empirical formula c3h40. what is the molecular formula of the compound?

What best discribes the relationship between wavelength and frequency in a electromagnetic wave