Acids, Bases, & Solutions. Solutions Solution-uniform mixture that contains a solvent & solute...
-
Upload
lorena-daughters -
Category
Documents
-
view
226 -
download
2
Transcript of Acids, Bases, & Solutions. Solutions Solution-uniform mixture that contains a solvent & solute...
Acids, Bases , & Solutions
Acids, Bases , & Solutions
SolutionsSolution-uniform mixture that contains a
solvent & solute Solvent-the part of the solution that is present in the
largest amount Solute-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 gases
Solutions have the same properties throughout
Colloids
a mixture that contains small undissolved particles, particles are too small to be seen, but large enough to scatter light
Suspension
Does not have the same properties through out
Contains visible particles
Effects of Solute & Solvents
Solutes lower the freezing point & raise the boiling point of a solvent
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)
Common solutionsSolute Solvent Solution
Gas Gas Air (oxygen and other gases in nitrogen)
Gas Liquid Soda water (carbon dioxide in water)
Liquid Liquid Antifreeze (ethylene glycol in water)
Solid Liquid Dental filling (silver in mercury)
Solid Liquid Ocean water (sodium chloride in water)
Solid Solid Stainless steel (chromium, nickel, and carbon in iron)
ConcentrationConcentrated solution-lots of
solute, little solventEx. Frozen juice
Dilute solution-little solute, lots of solventEx. Frozen juice + water
Measuring concentration-compare amount of solute to solventEx. 5 grams per 100mL
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
Factors affecting solubilityPressure
Increasing the pressure increases the solubility and vise-versa
Type of solventSome solutes & solvents are
incompatibleEx. Oil and vinegar
The solvent affects the solubility of a substance
Ex. Oil-based paint & water
TemperatureIncreasing the temp. of a solid
increases the solubilityIncreasing temperature of a gas
decreases the solubility
Acids and BasesAcids 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
AcidsTaste sourTurns blue litmus paper redReacts with metals/carbonatesContains hydrogen ions H+
Examples:Lemon juiceVinegarCar battery acid (dangerous!)
Some of our favorite foods make our tongue curl up because they are SOUR.
Acids and BasesAcids and Bases
Bases Taste bitter Feel Slippery Turns red litmus paper blue Contains hydroxide ions OH-
Turns Phenolphthalein pink Examples:
Milk Baking soda Soap Drain cleaner (dangerous!)
Bitter!
Some foods have a “bite” of their own because they’re somewhat bitter.
pH A special name given
to the acid or base characteristic is called: pH
How Do We Measure pH?
We measure pH by using special strips of paper called pH paper
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.
The pH ScalepH scale ranges from 0 -14pH 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
Acid
Any substance which has a pH value less than 7 is considered an acid
0--------------7---------------14
Acid Neutral Base
Base
Any substance which has a pH value greater than 7 is a base
0--------------7---------------14
Acid Neutral Base
pH 7
A pH of 7 is called neutral—neither acid nor base.
0-------------7------------14
Acid Neutral Base
The pH Scale
The pH Scale Each pH unit is 10 times as large as the
previous one A change of 2 pH units means 100 times more
basic or acidic
Each pH unit is 10 times as large as the previous one
A change of 2 pH units means 100 times more basic or acidic
x10 x100
Acid-Base Reactions
Neutralization-a reaction in which an acid reacts with a base to produce salt and water
HCl + NaOH= H2O + NaCl