Solutions and Suspensions

Solubility and

Rate of Dissolving

Solubility

Objectives: Understand the definition of solubility. Investigate the factors that affect the

solubility of various substances. Understand the definition of the rate of

dissolving. Investigate the factors that affect the rate

of dissolving of substances

Solubility

Solubility is the maximum amount of solute that can be dissolve in 100g of solvent at a given temperature

Solubility

ExampleWhat is the solubility of sugar in water at 25C if 28g of sugar can be dissolved in 250ml of water? (mass of 1ml of water is 1g)

Amt of sugar in 1g of water = 28 / 250 = 0.112gAmt of sugar in 100g of water = 0.112 x 100 = 11.2g

Solubility of sugar in water at 25C is 11.2g per 100g of water

Solubility

ExampleThe solubility of salt in oil at room temperature is 25g. How much salt can be dissolved in 200cm3 oil at room temperature? (density of oil is 0.9g/cm3)

Mass of 200cm3 of oil

= 0.9 x 200

= 180g

Solubility

Continue…

Amt. of salt that can be dissolved in 200cm3 of oil= 25 x 180/100= 45g

Solubility

Saturated Solution- A solution where maximum amount

of solute is dissolved in the solvent.

A B

Solubility

Factors affecting solubility: Temperature Nature of Solute Nature of Solvent

Solubility

The higher the temperature, the greater the solubility

Temp/°C

Solubility/ g per 100g of solvent

0

10

20

30

40

10 20

Solubility

Conclusion Solubility is the amount of solute

that can be dissolved in 100g of solvent

Saturated Solution has maximum solute in the solvent.

Temperature, nature of solvent and solutes affect solubility