Question

Would gravimetric analysis or colorimetry be more accurate when calculating the percentage yield of a precipitate?

Answer 1

I don't think there is a clear answer. First, a colorimetric measurement is difficult to do on a SOLID sample (reflectance perhaps) so we might be persuaded to choose gravimetric analysis. On the other hand, if there isn't enough sample to weigh accurately (say 1E-15 g is all you have) gravimetric analysis would be tough to do. I think you need to know WHAT it is (the identity of the material) AND approximately how much of the material is available.