Carbon dioxide affects o2binding to hb by: a) co2forming iron carbonate with the heme-iron atom. b) hb competing with carbonic anhydride for co2. c) directly binding to heme-fe in the oxygen binding site of hemoglobin. d) forming hco3- that combines with h+ to increase co2binding. e) forming h+ hco3- where the h is an antagonist to oxygen binding to hb.

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.