1. Solutions

2. A solution is a homogeneous mixture where all particles exist as individual molecules or ions. Mixtures in chemistry are combinations of different substances where each substance retains its chemical properties.

3. A solution is a homogeneous mixture. Homogeneous means that the mixture is the same all the way through. You could take two same-sized samples: one from the bottom and one from the top and they would be identical. Homogeneous mixtures do not settle out if left to sit undisturbed.

4. A solution has two components: the solute and the solvent. The solvent is the substance in greater amount. It does the dissolving. It is usually a liquid, but it doesn’t have to be. (It is usually water) The solute is the substance in lesser amount. It get dissolved. It is usually a solid, but it doesn’t have to be.

5. Like dissolves Like A polar solute dissolves in a polar solvent. A non-polar solute dissolves in a non- polar solvent. Other chemical properties also decide whether a solute will dissolve or not.

6. Saturation Saturated solution: contains the maximum amount of solute in a solvent. Unsaturated solution: contains less than the maximum amount of solute in a solution. Supersaturated solution: contains more than the maximum amount of solute in a solvent (this occurs when a solution is heated, solute added, then gradually cooled).

7. Factors affecting Solubility PRESSURE : only gases can be affected by pressure. TEMPERATURE : gaseous solutes require a cooler temperatures to increase solubility. : liquid and solid solute will dissolve more readily in hot solvents.

8. Factors affecting rate of dissolving Heating Stirring or Shaking Increasing surface area These processes all increase the number of interactions between solute and solvent.

9. The word concentration refers to how much solute is dissolved. It is a quantity. Dilute means that only a little solute is dissolved in a lot of solvent(20.0g or less per 100ml solvent). Concentrated means a great deal of solute is dissolved in a little solvent(20.0g or more per 100ml of solvent). For example, 100.0g HCl in a little water is concentrated, while 100.0g HCl in a lot of water is dilute.

10. Molarity measures concentration. Molarity = moles of solute litres of solution Ex: What is the Molarity of 53.5grams of calcium chloride dissolved in 362ml of solution? Change grams of solute to moles of solute. Divide moles of solute by litres of solvent. Divide moles of solute by litres of solvent.

11. 1 mole CaCl 2 = 111.0g CaCl 2 x 53.5g CaCl 2 x = 0.482 mol CaCl 2 Molarity = moles of solute litres of solute M = 0.482 moles 0.362 litres M = 1.33M

12. Suppose you had 58.44 grams of NaCl and you dissolved it in exactly 2.00 L of solution. What would be the molarity of the solution? 58.44g is 1.000 moles of NaCl Molarity = moles of solute litres of solution M = 1.000 mol 2.00 L M = 0.500 M

13. How many litres is needed to prepare a 0.876M solution of potassium nitrate that contains 12.0g of solute? 1 mole KNO 3 = 101.1g x = 0.119 mol x 12.0g M = Moles Litres 0.876M = 0.119 moles x litres x = 0.136 litres (or 136ml or 136 cm 3 )