The partial pressure of CO2 in air is approximately 4.0∗10−4 atm. If the Henry's-law constant is 3.2×10−2mol/(L⋅atm) to find the concentration of CO2 in: A. A can of soda under a CO2 pressure of 2.9 atm at 25 ∘C.
B. A can of soda open to the atmosphere at 25 ∘C.

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.