Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Jaime7078 on September 22, 2024, 01:45:18 PM
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the density of 2 m sulfuric acid solution is 1.12 kg per liter. what is the total molar concentration of the solution? what is the average molecular weight? what is the mass fraction of oxygen?
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molar concentration: 2M
average molecular weight:total mass = 1120g, mass of sulphuric acid = 2 mol × 98 g/mol = 196 g = 0.196 kg, Mass of water: 1.12 kg - 0.196 kg = 0.924 kg, Moles of water: 924 g / 18 g/mol = 51.33 mol, Total moles: 2 mol + 51.33 mol = 53.33 mol,Average molecular weight: 1120 g / 53.33 mol ≈ 21 g/mol.
mass fraction of oxygen: oxygen in water=821.33 g oxygen in h2s04=128 g, mass fraction = 84.7%
the thing is I dont if I should include water in my calculations because it doesn't specify that the solution is aqueous. I thinking I should have used that average molecular weight = density/concnetration or something
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the thing is I dont if I should include water in my calculations because it doesn't specify that the solution is aqueous. I thinking I should have used that average molecular weight = density/concnetration or something
Good catch, but if nothing else is given, assuming water solution is reasonable, this is the most common case.
Besides, 1.12 kg/L for 2M fits water solution.