Which of the following is a single replacement reaction? a. 2al + 6h2o > 2al (oh)3 + 3h2 b. ch4 + 202> co2 + 2h2o c. fe2o3 + 3h2o > 2fe(oh)3 d. agno3 + nacl> agcl + nano3

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.)