The visible red spectral line that results from the n = 3 to n = 2 transition of the hydrogen atom has a wavelength of 656 nm. Calculate the energy change that produces this spectral line.

The solid xy decomposes into gaseous x and y: xy(s) m x(g) + y(g) kp = 4.1 (at 0 °c) if the reaction is carried out in a 22.4 l container, which initial amounts of x and y will result in the formation of solid xy?