1) Hi i dont need the answer or anything i would just love if someone could explain to me where i must start with this problem and what exactly i should be thinking when i see MASS PERCENT. thanks!.
A 0.100 g sample of a carbon - hydrogen - oxygen compound is combusted in a stream of pure oxygen and produces 0.220 g CO2 and 0.239 g . What is the mass percent of hydrogen in the sample?[/b]
2) this just got me nowhere, i dont know where i should start what i should start with or anything, totally confused :(.
What thickness (in cm) is the silicon block (density = 2.33 g/cm3) that is 2.87 cm wide and long necessary to react with 91.3 g of Cr2O3 by the reaction: 3 Si (s) + 2 Cr2O3 (s) ? 3 SiO2 (s) + 4 Cr (l)?