If the density of an individual crystal of polyethylene (PE) is 0.983 g/cm3 and the density of totally amorphous polyethylene (PE) is 0.869 g/cm3, determine the fraction of crystallinity of a PE sample having density of 0.950 g/cm3 at the same temperature, (a) based on mass fraction, and (b) based on volume fraction.

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)