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Chapter 15 Solutions created by P. Perkerson. Why do we put salt in the ice when we make homemade ice-cream? . What is a solution? What forms (states of matter) can solutions take?. What is a solvent? What is a solute? What factors determine the rate a solute dissolves?.
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Chapter 15 Solutionscreated by P. Perkerson Why do we put salt in the ice when we make homemade ice-cream?
What is a solution? What forms (states of matter) can solutions take?
What is a solvent? • What is a solute? • What factors determine the rate a solute dissolves?
Describing solutions • A solution that has the maximum amount of solute is said to be saturated. • A solution with less than the maximum amount of solute is unsaturated. • A solution with more than the maximum (is that possible???) amount of solute is supersaturated.
Concentration of solutions is expressed in terms of molarity. A dilute solution will have a low concentration of solute and a concentrated solution will have a high concentration of solute. Molarity (M) is the number of moles of solute dissolved per liter of solvent. • M = moles solute L solution
Solution by dilution (molarity by dilution) is used when preparing acids of specific concentrations. • M1 x V1 = M2 x V2 (keep V units the same!)
Concentration can also be expressed in terms of: • Molality = moles of solute = moles of solute (m) kilograms solvent 1000 g
How would adding a solute to water affect its freezing and or boiling points? • A colligative property is one that depends on the number of particles in a solution. Freezing point depression and boiling point elevation are two examples of colligative properties. The more particles that the solute breaks into, the greater difference in freezing point and boiling point.
For example, when dissolving sodium chloride in water it breaks into two types of particles sodium ions and chloride ions so it raises the boiling point of water and lowers the freezing point. When you dissolve sugar in water it breaks into only one type of particle (because it is covalent it breaks into molecules) so it doesn’t affect the BP or FP.