The solubility of Cr(NO3)3⋅9H2O in water is 208 g per 100 g of water at 15 ∘C. A solution of Cr(NO3)3⋅9H2O in water at 35 ∘C is
formed by dissolving 310 g in 100 g water. When this solution is slowly cooled to 15 ∘C, no precipitate forms. At equilibrium, what mass of crystals do you expect to form?
When the Cr(NO₃)₃⋅9H₂O is dissolved in water at 15°C, the maximum mass that water will dissolve in the equilibrium is 208 g per 100g of water. When you heat the water, this mass will increases.
In this problem, at 35°C the water dissolves 310g in 100g of water, as in the equilibrium at 15°C the maximum mass is 208g, the mass of crystals that will form is:
310g - 208g = <em>102g of crystals</em>
<em>-Crystals are the Cr(NO₃)₃⋅9H₂O that is not dissolved-.</em>
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