Question

Consider a random mixture containing particles of na2so4 and k2so4. there are 11.53 g of na2so4 (density 2.639 g/ml) and 88.47 g of k2so4 (density 2.467 g/ml) in the mixture. all particles in the mixture have a uniform spherical radius of 0.075 mm.
a.calculate the mass of a single particle of na2so4 and the number of na2so4 particles in the mixture.

Answer 1

Since it talks about the number of particles, we would need the Avogadro's number which is an empirical value equal to 6.022×10²³ particles/mole. The other information that we have to know is the molar mass of Na₂SO₄ which is 142.04 g/mol.

Mass of a single particle of Na₂SO₄:
(142.04 grams Na₂SO₄/mol) * (1 mol/6.022×10²³ particles) = 2.359×10⁻²² g
Thus, each Na₂SO₄ weighs 2.359×10⁻²² g.

Number of Na₂SO₄ particles in the mixture:
(11.53 g Na₂SO₄) * (1 mol/142.04 g) * (6.022×10²³ particles/mol) = 4.89×10²² particles
Thus, the mixture contains 4.89×10²² particles is Na₂SO₄.