How much potassium nitrate do i need to make 21g of nitric acid?

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.

In the space, show a correct numerical setup for calculating the number of moles of co2 present in 11 grams of co2

Chlorophyll a had the molecular formula c55h72mgn4o5 how many atoms are in this molecule