Which of the following statements is true?
a. unsaturated solutions will not dissolve more solute.
b. for most substances, the solid state is more dense than the liquid state.
c. density is not temperature dependent.
d. a nonpolar solute will dissolve in a polar solvent such as water.

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.