you take 295.5 g of a solid at 30.0 c and let it melt in 425 g of water. the water temperature decreases from 85.1 c to 30.0 c. calculate the heat of fusion of this solid

What is the relation between concentration of reactants and the rate of chemical reaction?

What is the percent by mass of oxygen in fe2o3

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.