In what substances is the mole fraction of oxygen equal to its mass fraction?

In what substances is the mole fraction of oxygen equal to its mass fraction? O3 CO2 HNO3 HPO3 Cu2 (OH) 2CO3 CH3COOH H2O Fe2 (SO4) 3

The mole fraction of oxygen is equal to the mass fraction of the substance in all of the listed compounds.

The mass fraction of a substance is determined by the formula

v = mtot / mtotal, where mvt is the mass of that part of the substance, the mass fraction of which you want to know; mtot. – the total mass of the substance. For example:

– for O3 v = 16 * 3/16 * 3 = 48/48 = 1 or 100% (mass fraction of oxygen in ozone)

– for HNO3 v = 16 * 3 / (1 + 14 + 16 * 3) = 48/63 = 0.76 or 76% (mass fraction of oxygen in nitric acid);

The mole fraction is determined by the formula: g = ntot / ntot, where g = ntot is the number of moles of the substance, the mole fraction of which needs to be known, ntot is the number of moles of the substance.

For example:

1 mol O3 – 48 g (molar mass), in it x mol of oxygen weighing 48 g,

Total x = 1 mol.

g = 1/1 = 1 or 100% (mole fraction of oxygen in ozone).

For nitric acid

1 mol of HNO3 – 63 g, in which x mol of oxygen weighing 48 g.

Total x = 1 * 48/63 = 0.76 mol

g = 0.76 / 1 = 0.76 or 76% (mole fraction of oxygen in nitric acid)