Chapter 3: Acids, Bases, and Solutions
Section 1: Working With Solutions
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Solutions and Suspensions
Suspension: particles are easily seen and easily separated by settling or filtering
Ex. Pepper water
Solution: a well-mixed mixture, particles are smaller than suspension, no separation with
filtering
Ex. Salt water (evaporation can separate)
Solvents and Solutes
Solvent: Part of solution found in largest amount—dissolves solute
Solute: Part of solution found in smaller amount—is dissolved by solvent
Water as a Solvent
Water—“universal solvent”
Solutions Without Water
Solutions do not require liquids
Solutions can be made of combinations of solids, liquids, gases
Particles in a Solution
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Particles of the solute divide (leave each other) and are surrounded by particles of solvent
 Ionic Solids in H20
(+) and (-) ions are attracted to H20 molecules and leave crystal
 Molecular Solids in H20
Molecules break into individual neutral molecules
Attraction to H20 causes the molecules to move apart and become surrounded by H20
 Solutions and Conductivity
Electricity will be conducted—flow through ionic compounds
Ex: Through salt water not sugar water
Concentration
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Amount of solute compared to the amount of solvent
Dilute solutions—little solute
Concentrated solutions—more solute
Solubility
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How well a solute can dissolve in a solvent at a certain temperature
Saturated solution—no more solute will dissolve
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Unsaturated solution—more solute will dissolve
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Solubility can be used for identification
Changing Solubility
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Temperature of solvent
Type of solvent
Temperature: solids (like sugar) dissolve better at higher temperatures
Temperature: gases become less soluble at higher temperatures
Solvent: “likes dissolves like”
Ionic/polar dissolve in polar solvents
Non-polar do not dissolve in polar solvents
Effects of Solutes on Solutions
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Lower Freezing Point: Solutes lower the freezing point
Higher Boiling Points: Solutes raise the boiling point
Section 2: Describing Acids and Bases
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Properties of Acids
Acids: taste sour, react with metals, react with carbonates, turns blue litmus paper red
Sour Taste
Citric acid gives many fruits their taste
Ex. Vinegar, tea, spoiled milk
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Reaction with Metals
Acids react with some metals to produce H2 gas (Mg, Zn, Fe)
Corrosive—“eat away” materials
Etching—controlled metal corrosion
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Reaction with Carbonates
Carbonate ions (C) and (O) bonded together (CO3-2) negative charge of 2
React with carbonate to form CO2
Ex. Baking Soda
Limestone (Calcium Carbonate) reacts with HCl
Ex. Coral, chalk
Reactions with Indicators
Indicators change color when in contact with an acid or base
Acids—turn blue litmus paper red
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Properties of Bases
Bases: taste bitter, feel slippery, turn red paper blue
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Bitter Taste
Ex: tonic water, soap, shampoo
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Slippery Feel
Ex: soap
May irritate skin
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Reaction with Indicators
Red Litmus to Blue (Base to Blue)
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Reaction of Bases
Do not react with carbonates or metals
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Uses of Acids
Acids in foods
Digests food in body
Bi-products of cell respiration in exercise
Dilute acids—cleaning products
Fertilizers
Car battery
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Uses of Bases
Baking Soda produces C02—used for “rise”
Base and Health—counter act the acidity of stomach acid
Cleaners
Fertilizers
Mortar/cement