Solutions Chapter 8.1 & 8.2

Formation Any states of matter - solid, liquid, or gas – can become part of a solution For a solution to form, one substance must dissolve in another 2 components: solute – a substance whose particles are dissolved in a solution; its what you want to dissolve solvent – the substance in which the solute dissolves

U put solute in solvent solution - a homogeneous mixture of two or more substances Example: Salt Water Which one dissolves? In what? U put salt in water & it becomes a solution In a solution, the solvent is the substance in the greatest quantity or amount

Type of Solutions SoluteSolvent ***(you don’t have to copy this page)*** Gas Air (solution of O 2, CO 2 and N 2 ) LiquidGasWater in air (water vapor or steam) GasLiquidCarbonated beverages like soda (CO 2 in H 2 O) Liquid Vinegar (acetic acid in water) SolidLiquidSugar water (sugar in water) Solid Stainless steel (chromium & nickel in iron)

Factors Affecting Rates of Dissolving During the formation of a solution, collisions occur between particles of the solute and solvent Number of collisions can increase due to 3 things: surface area, stirring, & temperature.

3 ways to Speed it up 1 – break it up to increase surface area 2 - stir it up so it has more collisions w/ other particles 3 - heat it up so the particles move faster (Kinetic Theory of Matter!)

Solubility & Concentration There are limits to how much solute you can get to dissolve in a solvent solubility – the maximum amount of solute that dissolves in a given amount of solvent at a constant temperature Solubility is usually expressed in grams of solute per 100 grams of solvent at a specified temperature concentration – amount of solute dissolved in a specified amount of solution

Solubility in 100 g of Water at 20˚C CompoundSolubility (g) Table salt (NaCl)36.0 g Baking soda (NaHCO 3 ) 9.6 g Table sugar (C 12 H 22 O 11 ) g

How much is in it? Solutions are described as saturated, unsaturated, or supersaturated, depending on the amount of solute in solution

Saturated saturated solutions – a solution that contains as much solute as the solvent can hold at a given temperature When a solution is saturated, the solvent is “filled” with solute. If you add more solute & don’t increase the temperature, the solute will not dissolve in the solvent

Unsaturated unsaturated solution – a solution that has less than the maximum amount of solute that can be dissolved If a solution is classified as unsaturated, you can add more solute and it will dissolve without having to increase the temperature

Supersaturated supersaturated solution – a solution that contains more solutes than it can normally hold at a given temperature Supersaturated solutions are very unstable

Solubility Curve