Solubility Curves

Solubility CurvesSolubility

the maximum amount of substance that can dissolve in a given volume at a given temperature

Solubility CurvesSolubility Curve

Graphing solubility (y-axis) vs temperature (x-axis)

SaturatedSolute (g) per 100 g

H2O(l)

Temperature

Unsaturated

Supersaturated

On the line = saturated (full and cannot hold anymore solute)

Below the line = unsaturated (can hold more solute)

Above the line = supersaturated (holding more solute than it should, unstable condition)

Solubility CurvesExample A –

is this point unsaturated, saturated or supersaturated?

Solute (g) per 100 g

H2O(l)

Temperature

Solubility CurvesExample B –

is this point unsaturated, saturated or supersaturated?

Solute (g) per 100 g

H2O(l)

Temperature

Solubility CurvesExample C –

is this point unsaturated, saturated or supersaturated?

Solute (g) per 100 g

H2O(l)

Temperature

“Real” Solubility Curve

Calcium chloride (CaCl2) has a solubility of about 64 g CaCl2 per 100 g H2O at what temperature?

Answer: 10 °C

“Real” Solubility Curve

If we had 70 g of CaCl2 at 10 °C, would our solution be unsaturated, saturated or supersaturated?

Answer: supersaturated

“Real” Solubility Curve

How many grams of KCl is needed to make a saturated solution in 100g of H2O at 70 °C?

Answer: 49 g

“Real” Solubility Curve

Potassium chlorate (KClO3) is an unsaturated solution at 90 °C as long as the mass is under _____ g.

Answer: 40 grams

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