1. For each buffer, determine the volume of HCl and NaOH needed to change the pH by 1 unit. You may need to estimate this value if it is not directly observed in your data. Using your volumes, calculate the number of moles of HCl and NaOH that reacted with each buffer. (This is the capacity of each buffer.)

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.