Does anyone know how to find the overall density of an aqueous solution?

Question

I am given the density of water at 1.00g/ml and ethanol at 0.789g/ml. How do I combine these to get the overall density of the solution when they are mixed together?

Answer 1

The problem is that water and ethanol when mixed, do not contain a solution with a volume equal to the combined volumes of the two solutions. It always seems to be less. In addition, the density is a function of temperature.

Aqueous ethanol solutions need to have their densities measured and not calculated. This is experimental not theoretical.

Check out the reference below for additional details, including the densities of Aqueous ethanol solutions from zero to 100 percent.

A very crude approximation can be calculated by taking the volume of the water X 1.00g/mL (giving grams of water) and adding the volume of ethanol X 0.789 g/mL (giving grams of alcohol). This gives the total grams of the solution. Divide this by the total volume (volume of water plus volume of ethanol) to get an approximate density of the combines solution.

Answer 2

a million) Mole fraction implies to understand the style of moles of ethanol and moles of water (assuming that the solvent is water) because of the fact: molar fraction of ethanol = moles of ethanol / (moles of ethanol + moles of water)..... (Eq1) 2) Density of answer is 0.964 g/mL If answer is 3.05 M in ethanol in accordance to the definition of molarity, the quantity of answer may well be assumed a million liter, for this reason: d = m/V we remedy for mass: m = dV = (0.964 g/mL)(1000 mL) = 964 g on the different hand, 3.05 moles of ethanol (save in mind that molecular mass of ethanol = 40 5 g/mol) are equivalent in mass to : m = nM = (3.05 moles)(40 5 g/mol) = 137.25 g 3) we can substract from the full mass of answer, the mass of ethanol: m water = 964 g - 137.25 g = 826.75 g 4) Now we can compute the moles of water: n = 826.75 g / 18g/mol = 40 5.ninety 3 moles 5) ultimately, we can compute the molar fraction in accordance to equation (Eq1): molar fraction = 3.05 / (3.05 + 40 5.ninety 3) = 3.05 / 40 8.ninety 8 = 0.0622 that's it!