2 Solutions Solution-uniform mixture that contains a solvent & solute Solvent-the part of the solution that is present in the largest amountSolute-the part of the solution that is present in the smaller amount and is dissolved…Water is the universal solvent, but solvents and solutes may be solids, liquids, or gasesSolutions have the same properties throughout
3 Colloidsa mixture that contains small undissolved particles, particles are too small to be seen, but large enough to scatter light
4 Suspension Does not have the same properties through out Contains visible particles
5 Effects of Solute & Solvents Solutes lower the freezing point & raise the boiling point of a solvent
6 Particles in SolutionWhen a solution forms, particles of the solvent surround and separate the particles of the solute. Ionic and molecular compounds in solution Ionic – positive and negative ions are attracted to the polar water molecules. These types of compounds in water will conduct electricity. Molecular – breaks up into individual neutral molecules (sugar)
7 Common solutions Solute Solvent Solution Gas Air (oxygen and other gases in nitrogen)LiquidSoda water (carbon dioxide in water)Antifreeze (ethylene glycol in water)SolidDental filling (silver in mercury)Ocean water (sodium chloride in water)Stainless steel (chromium, nickel, and carbon in iron)
8 Concentration Concentrated solution-lots of solute, little solvent Ex. Frozen juiceDilute solution-little solute, lots of solventEx. Frozen juice + waterMeasuring concentration-compare amount of solute to solventEx. 5 grams per 100mL
9 SolubilityHow much solute can dissolve in a solvent at a given temperatureUnsaturated-can hold more soluteSaturated-can NOT hold more soluteSupersaturated-too much solute, some is undissolved at the bottom of the container
10 Factors affecting solubility PressureIncreasing the pressure increases the solubility and vise-versaType of solventSome solutes & solvents are incompatibleEx. Oil and vinegarThe solvent affects the solubility of a substanceEx. Oil-based paint & water
11 Temperature Increasing the temp. of a solid increases the solubility Increasing temperature of a gas decreases the solubility
12 Acids and Bases Chemicals may be classified as acids or bases. Things that are neither acids nor bases are neutral.pH measures the acidicity or basidity of a solution
13 Acids Taste sour Turns blue litmus paper red Reacts with metals/carbonatesContains hydrogen ions H+Examples:Lemon juiceVinegarCar battery acid (dangerous!)
14 Acids and BasesSome of our favorite foods make our tongue curl up because they are SOUR.
15 Bases Taste bitter Feel Slippery Turns red litmus paper blue Contains hydroxide ions OH-Turns Phenolphthalein pinkExamples:MilkBaking sodaSoapDrain cleaner (dangerous!)
16 Bitter!Some foods have a “bite” of their own because they’re somewhat bitter.
17 pHA special name given to the acid or base characteristic is called: pH
18 How Do We Measure pH?We measure pH by using special strips of paper called pH paper
19 How Does It Work?The paper is treated with chemicals that change color to show the pH.When the paper touches the substance being tested, it turns a specific color to tell if the substance is an acid or a base.
20 The pH Scale pH scale ranges from 0 -14 pH 7 is neutral; neither acid nor basePure water is pH 7Low pH = acidHigh pH = baseThe closer to the ends of the scale, the stronger the solution
21 0--------------7---------------14 AcidAny substance which has a pH value less than 7 is considered an acidAcid Neutral Base
22 0--------------7---------------14 BaseAny substance which has a pH value greater than 7 is a baseAcid Neutral Base
23 pH 7 A pH of 7 is called neutral—neither acid nor base. Acid Neutral Base