Combining 0.280 mol Fe2O3 with excess carbon produced 13.8 g Fe. Fe2O3+3C⟶2Fe+3CO
What is the actual yield of iron in moles?

Molarity is moles of solute over liters of solution. idk if that is what you are talking about, but you can convert moles of solute to grams of solute using dimensional analyzes by using molar mass found on the periodic table.

Answer(true);

Polymerization reaction

Ican't see the chart but the density of both nickel and cobalt is 8.90 g/cm3, so it would be one of those.