Acetylsalicylic acid, the active ingredient in aspirin, is prepared from salicylic acid by reaction with acetic anhydride.C7H6O3 (salicylic acid) + C4H6O3 (acetic anhydride) → C9H8O4 (acetylsalicylic acid) + C2H4O2 (acetic acid)Calculate the theoretical yield if 47 g of salicylic acid is reacted with 25 g of acetic anhydride.

Acrylonitrile (C­₃H₃N) is the starting material for many synthetic carpets and fabrics. It is produced by the following reaction: 

2 C₃H₆ (g) + 2 NH₃ (g) + 3 O₂ (g)  → 2 C₃H₃N (g) + 6 H₂O (g)

If 12.0 g C₃H₆, 10.0 g NH­₃, and 5.0 g O₂ react, what mass of acrylonitrile can be produced, assuming 100% yield?

The reaction between solid aluminum and iron (III) oxide can generate temperatures reaching 3000 ºC and is used in welding metals. 

2 Al + Fe₂O₃ → Al₂O_­3 + 2 Fe

If 150 g of Al are reacted with 432 g of Fe­₂O₃, what is the mass of the excess reactant remaining?