Please help me im going out of my way and giving you extra points I really need some assistance Read the given chemical reaction.

C2H6 + O2 → CO2 + H2O

How many moles of H2O are produced during the complete combustion of 1.4 moles of C2H6?

2.8 moles
4.2 moles
5.6 moles
7.0 moles

What is the percent by mass of oxygen in fe2o3

Ineed ! i have no clue how to do this problem.

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.)