Hemoglobin is the protein that transports oxygen in mammals. Hemoglobin is 0.347% by mass, and each hemoglobin molecule contains four iron atoms. Calculate the molar mass of hemoglobin. Molecular mass

Asample of hydrated tin (ii) chloride (sncl2) has a mass of 4.90 g. when it is dehydrated, it has a mass of 4.10 g. which is the correct chemical formula for the hydrate? sncl2•2h2o          sncl2•4h2o          sncl2•6h2o