Presentation on theme: "Solution, Acids and Bases"— Presentation transcript:
1 Solution, Acids and Bases Chapter 6Solution, Acids and Bases
2 Mixtures Two or more substances Heterogeneous- different from place to placeTypes of heterogeneous mixturesSuspensions- Large particles that eventually settle outRiver water, pulp in orange juiceCan be separated by filtering1000 nm in size
3 Heterogeneous Mixtures Colloids- smaller sized pieces nmThey do not settle,They can’t be separated by filteringBlood, fog, smoke, whipped creamImmiscible- liquids that don’t dissolveWill separate into layersOil and vinegar
4 Mixtures Emulsions- colloids of liquids and liquids Proteins in egg yolk keep immiscible oil and vinegar together- mayonnaiseMilk and creamHomogeneous mixtures- the same throughout, no piece bigger than an individual ion or atom
5 Solutions homogenous mixtures mixed molecule by molecule. Solvent - the stuff that does the dissolving.Solute -the stuff that is dissolved.Solutions can be any statesAqueous solution- a solution with water as the solvent.Most common
6 Solutions Miscible- Liquids that dissolve in each other Do not separate into layersCan be separated by distillation if boiling points are different enoughLower boiling point evaporates fastest
7 How Ionic solids dissolve Called solvation.Water is a polar moleculeOxygen pulls more on the electronsGets a partial negative chargeHydrogens get a partial positive chargeIonic compounds have + and - piecesWater breaks the + and - charged pieces apart and surround them.
9 Making solutions What the solute and the solvent are Whether a substance will dissolve.How much will dissolve.A substance dissolves faster if-It is stirred or shaken.The particles are made smaller.The temperature is increased.Why?
10 Making solutionsIn order to dissolve the solvent molecules must come in contact with the solute.Stirring moves fresh solvent next to the solute.The solvent touches the surface of the solute.Smaller pieces increase the amount of surface of the solute.
11 Temperature and Solutions Higher temperature makes the molecules of the solvent move around faster and contact the solute harder and more often.Speeds up dissolving.Usually increases the amount that will dissolve.
12 How Much?Solubility- The maximum amount of substance that will dissolve at that temperature (usually g/L).Saturated solution- Contains the maximum amount of solid dissolved.Unsaturated solution- Can dissolve more solvent.Supersaturated- A solution that is temporarily holding more than it can, a seed crystal will make it come out
13 What affects solubility? For solids in liquids as the temperature goes up the solubility goes up.For gases in a liquid as the temperature goes up the solubility goes down.For gases in a liquid- as the pressure goes up the solubility goes up.
14 Measuring Concentration Amount dissolved divided by amount of solvent% solution= grams dissolved x100% Grams of solutionMolarity = moles of solute Liter of solutiona 1 molar solution has 1 mole dissolved in 1 liter of solution.
15 Acids Substances that donate hydrogen ions (H+) to water to form H3O+ Called the hydronium ionHCl hydrochloric acid used in poolsH2SO4 sulfuric acid- battery acidHC2H3O2 acetic acid- vinegarHC6H7O7 citric acid- lemons, limes
16 Properties of acids Taste Sour (kids, don’t try this at home). Conduct electricity.Some are strong, some are weak electrolytes.React with metals to form hydrogen gas.Change indicators (litmus red).React with hydroxides to form water and a salt.
17 Acids The ones in food are dilute Concentrated acids are dangerous They can burn you skin and eyesStrong acids ionize completelyAll the H’s make hydroniumHCl + H2O Cl- + H3O+Makes lots of ionsAre dangerous
18 Acids Weak acids only partially ionize Only a few H’s attach to water HC2H3O2+ H2O C2H3O2- + H3O+Can be dangerous if concentrated
19 Bases Increases the amount of OH- in solution Either has OH- in it Or takes an H off of waterKOH - in drain cleanerNaOH - in drain cleanerNH3- ammonia
20 Properties of bases Taste bitter. Feel slippery (Don’t try this either).Can be strong or weak electrolytes.Change indicators (litmus blue).React with acids to form water and a salt.
21 Bases KOH K+ + OH- Strong bases ionize completely Make lots of ions Are dangerousNH3 + H2O NH4+ + OH-Weak acids only make a few ionsAre dangerous if concentrated
22 How Acidic? More H3O+ is more acidic Measured with pH Lower pH is more acidicAs H3O+ goes down, OH- goes upHigher pH more basicpH of 7 is neutralAcidicNeutral7Basic14
23 pH Measures hydronium ion concentration Every 1 unit less of pH is 10 times more hydroniumA pH of 2 is 100 time more H3O+ ions than a pH of 4pH is number of places after the decimal pointpH of 2 is 0.01 Molar H3O+pH of 4 is Molar H3O+pH of 9 is Molar H3O+
24 pH Low pH is acid Lots of H3O+ Little OH- High pH is base Little H3O+ Lots of OH-
25 Neutralization Reactions Acids and bases react and neutralize each otherStrong acids make lots of ionsHCl + H2O H3O+ + Cl-Strong bases make lots of ionsNaOH Na+ + OH-andH3O+ + OH- 2H2O
26 Neutralization Reactions Put acids and bases togetherH3O+ + Cl- + Na+ + OH- Cl- +Na+ +2H2OThe Na+ and Cl- make salt which is neutralWater is neutralAll ionic compounds are saltsWill be neutral if the right amounts of strong acids and bases are added
27 Neutralization Reactions Weak bases will neutralize a strong acid, but not as well.You need to add more of themIf you add enough, it will make the solution basicSame works for weak acids and strong basesAs you add acid to a base the pH dropsAs you add base to and acid the pH rises
28 Soap Water and oil don’t mix Water is polar Oil is nonpolar Soap can dissolve in both oil and waterMade by mixing fats with lye (NaOH)
36 Water molecules can surround and dissolve grease. Helps get grease out of your way.
37 DetergentsSoaps react with minerals in hard water and form scum that doesn’t dissolveDetergents have the same basic structure but have a sulfur at the end,And start from petroleumDissolve in hard water
38 Ammonia NH3 dissolved in water makes a weak base NH3 + H2O NH4+ + OH- The OH- ion reacts with grease and makes an emulsion which can wash awaySlippery
39 Household UsesAntacids- Weak bases that neutralize excess stomach acidShampoo- made from detergentsNeed to keep pH between 5 and 8 or it will make the hair dullCitric acid keeps fruit from browningAcidic marinades tenderize meatsDrain cleaners are strong bases