I think the answer is c since the it’s looking at NW, the wind is coming from SE
Convert 0.47g 2-naphthol to mols. mol = g/molar mass.
Using the coefficients in the balanced equation, convert mols 2-naphthol to mols 2-butoxynaphthalene then you have to Convert mol 2-butoxynaphthalene to grams. g = mols x molar mass. This is the theoretical yield.
Two 1+ ions are needed in order to balance one 2- ion.