Myoglobin is a globular protein, with molar mass m ≈ 17,000g/mole. The buoyant correction typically reduces m to m' ≈ 0.25m. Calculate the concentration ratio of the protein at the top of a 4 cm test tube and that at the bottom. Here, m' stands for effective mass. I tried as below. I used the equation of buyoancy so that the effective mass reduce into 0.25m. m'g = (ρ-ρ')Vg = 0.25mg = 0.25ρVg (ρ is the density of myoglobin, and ρ' is the density of water) → 0.75ρ = ρ' So since ρ > ρ', I think the myoglobin should sink to the bottom of the test tube. As a result, the concentration of myoglobin at the top is 0 and let the concentration of the bottom is M. Then, concentration ratio of bottom and the top becomes 0 / M which gives me 0. However, I don't think my answer is reasonable. Why does the problem give me the molar mass? I hope anyone could ever help me.