Answer :
To find the mole fraction of acetylacetone (acac) in a mixture with water, calculate the moles of acac and water separately using their densities and molar masses, and then divide the moles of acac by the total moles of both substances in the solution.
Calculating Mole Fraction of Acetylacetone (acac)
To calculate the mole fraction, we need to determine the number of moles of each component in the solution. For acetylacetone (acac), we would use its density and molar mass to find the number of moles. Assuming we know the density of acac to be approximately 0.97 g/mL, we can calculate the mass of 4.00 mL of acac as:
Mass of acac = Volume \'d7 Density = 4.00 mL \'d7 0.97 g/mL = 3.88 g
Next, using the molar mass of acac (100.17 g/mol), we calculate the moles of acac as:
Moles of acac = Mass / Molar mass = 3.88 g / 100.17 g/mol
For water, we assume the density to be 1 g/mL, so the mass of 6.00 mL of water would be 6.00 g. The molar mass of water (H2O) is 18.02 g/mol, therefore the number of moles of water is:
Moles of water = Mass / Molar mass = 6.00 g / 18.02 g/mol
The mole fraction of acac is then calculated by dividing the moles of acac by the total moles of both substances in the solution:
Mole fraction of acac = Moles of acac / (Moles of acac + Moles of water)
The mole fraction is a way to express the ratio of the number of moles of a component to the total number of moles of all components in the solution. It provides a measure of concentration without the need of volume units, useful for reactions and properties calculations where volume changes are negligible.
