(a) A 10.76-g sample of impure CsF was dissolved in 100 mL water. Th e sample was mixed with excess aqueous calcium nitrate solution to precipitate insoluble calcium fluoride. Th e precipitate was filtered, dried, and weighed. A total of 2.35 g calcium fluoride was collected. What was the percentage of CsF in the original sample?

(b) Given the reaction

what volume of HF (g) is produced at standard temperature and pressure (STP) if 100.0 g CsF reacts?

(c) CsF is not only colorless but transparent to infrared light up to a wavelength limit of 15.0  μm. What is the energy of a photon of light having that wavelength? What is the energy of a mole of photons of that wavelength? How many moles of photons are needed to supply the same amount of energy as produced in the reaction given in the Case Study?

Transcribed Image Text:

CsF(s) + HNO3(aq)→ HF(g) + CsNO3(aq)