Transcript Chapter 9 * Acids and Bases

Chapter 9 – Acids and Bases
BELLWORK
Pure vinegar is an acid,
called ________ acid
Chapter 9 – Acids and Bases
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Key Questions:
1] What are the properties of acids?
2] What are the properties of bases?
3] How is pH related to the concentration of
hydronium ions and hydroxide ions in
solution?
• 4] What are some household products that
contain acids, bases, and salts?
State Standards
• CLE.3202.1.10 – Distinguish among acids,
bases, and neutral substances
• CLE.3202.Inq.2 – Recognize that science is a
progressive endeavor that reevaluates and
extends what is already accepted
Key Terms
- Acid : Lose an H+ ion when ionized or dissolved in
water. Acids are corrosive, taste sour, conduct
electricity, and turn indicators different colors
- Indicator : Compound that reversibly changes
colors depending on pH
- Electrolyte : Substance that dissolves in water
enabling solution to conduct electricity
Key Terms
- Base : Lose OH- when ionized or dissolved in water.
Bases have bitter taste, and their solutions feel
slippery. These solutions can also conduct electricity,
turn indicators colors, and damage skin
- pH : Value used to describe the amount of acidity or
basicity ( each whole number on a scale from 0-14
indicates a tenfold change in acidity )
- Salt : A compound that has a negative ion and a
positive ion bonded together ( NaCl )
Water
• H2O  H3O+ + OH• Balanced?
• Dissolves itself to form H3O+ and OH– Hydronium and Hydroxide
Everyday Acids
• Citrus fruits, such as lemons, limes, and oranges,
contain citric acid. Apples contain malic acid;
grapes contain tartaric acid.
• Acids increase amount of H3O+ when added to
water (Acids lose H+ ions but water gains them!! )
Everyday Bases
• Bases increase amount of OH- when
added to water
– Bases may lose OH- but not always
– As opposed to acids ( how? )
• Common household cleaners ( ammonia based )
Everyday Salts
• Salts are not acids & bases
( but similar )
– They both can dissolve
when added to water
• Common types:
– Soap ( salts of Na or K and
long hydrocarbon chains
– Detergents
– Salt ( Duuhh!! )
Indicators
• Acids turn Blue Litmus paper Red
• Bases turn Red Litmus paper Blue
• Demonstration – What happened?
– Vinegar
– Lemon Juice
– Sodium Hydroxide ( NaOH )
– Milk of Magnesia
– Tap water
pH
• pH values correspond to the amount of
hydronium ions
Why It Matters
• Normal rain has a pH of about 5.6, so it is
slightly acidic. Acid rain is a type of pollution
in which the precipitation has a pH that is less
than 5.0. Acid rain results from emissions of
sulfur dioxide, SO2, and nitric oxide, NO, which
are gases from coal-burning power plants and
automobiles. The gases react with compounds
in the air to form sulfuric acid, H2SO4, and
nitric acid, HNO3.
Why It Matters
• Acid rain is a type of pollution that can have
harmful effects on many parts of the
environment, including animals, plants, and
buildings
• Mercury ingestion – acid rain causes more
organic mercury to form in lakes, streams, etc
• Organic mercury absorbs more easily in the
human body!!
Chapter 9 – Acids and Bases
Key Questions:
1] What are the properties of acids?
2] What are the properties of bases?
3] How is pH related to the concentration of
hydronium ions and hydroxide ions in solution?
4] What are some household products that
contain acids, bases, and salts?