A solution that has a molarity of 1.5 M needs to be diluted to create 100. ml of a 0.25 M solution. How many milliliters of the 1.5 M solution should be used to make this dilution? Your answer should contain the correct number of significant figures. You must show your work​

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.