A deep underground cavern contains 3.35 × 10 ^ 6 L of ethane gas ( C2 H6) at a pressure of 2.50 × 10 ^ 3 kpa & temperature of 370 degree Celsius. How many grams of C2H6 does the cavern contain? ( R = 8.31 L. kpa / K/mol)

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.)