Scientists theorized that acids were made of sharply pointed particles that literally pricked the tongue or scratched the metal.
Acids and bases and salts
• Acid and base are terms used by chemists to categorize
chemicals according to their pH.
•An acid is generally considered to be any material that gives
up a hydrogen ion in solution,
• While a base is any material that creates a hydroxide ion in
•Many of these acids and bases are familiar in everyday life.
A class of compounds whose water
solutions taste sour, turn blue litmus to
red, and react with bases to form salts.
Acids produce solutions that:
• Taste sour
• Turn blue litmus paper red
• Conduct electricity
• react with metals to liberate a hydrogen gas
• are corrosive (acid rain)
• lose the above properties when reacted with a base.
Examples of acids:
• Lemon Juice
• Soft Drink
• Battery Acid
• Stomach Acid
• Apple Juice
• Black Tea
• Strong Acids – any acid that dissociates completely in aqueous solution.
• Weak Acids – any acid that dissociates only partially in aqueous solution.
Strong Acids Weak Acids
1. chloric acid, HClO3
2. hydorbromic acid, HBr
3. hydorchloric acid, HCl
4. sulfuric acid, H2SO4
5. nitric acid, HNO3
1. acetic acid, Ch3COOH
2. boric acid, H3BO3
3. hydorfluoric acid, HF
4. phosphoric acid, H3PO4
5. sufurous acid, H2So3
A class of compounds that taste
bitter, feel slippery in water solution,
turn red litmus to blue, and react with
acids to form salts.
Bases produce solutions that:
• taste bitter
• turn red litmus blue
• conduct electricity
• feel slippery
• are corrosive (basic solution in glass container)
• lose the above properties when reacted with an acid.
Examples of bases:
• Baking Soda
• Drain Cleaner
• Soaps (hand, dish)
• Strong Bases – any base that dissociates completely.
• Weak Bases – any base that dissociates only partially in aqueous solution.
Strong Bases Weak Bases
1. barium hydroxide, Ba(OH)2
2. calcium hydroxide, Ca(OH)2
3. potassium hydroxide, KOH
4. sodium hydroxide, NaOH
5. trisodium phosphate, Na3PO4
1. ammonia, NH3
2. aniline, C6H5NH2
3. potassium carbonate,K2CO3
4. sodium carbonate, Na2CO3
5. trimethylamine, (CH3)3N
• These are items that are neither acids or
• Neutral items will turn blue and red litmus
• The main example of a neutral item is:
• Red litmus paper
• Blue litmus paper
• Red Cabbage Juice
•Robert Boyle discovered litmus paper
•certain plant extracts, such as litmus, can be
used to distinguish acids from bases.
• blue and red litmus paper turn red when
dipped in an acid
• red and blue litmus paper turn blue when
exposed to a base
• red cabbage can be used as an acid/base
• after boiling the red cabbage, pour a small
amount of the juice into a small sample of a
substance your checking
• the juice will turn blue if the substance is a
• the juice will turn red if the substance is an
• DNA contains thousands of sites where
H+ ion transfer can take place
• Therefore DNA fits the definition of a
• DNA is a weak acid, but it is stronger
than phosphoric acid.
• ACID - A class of compounds whose water solutions
taste sour, turn blue litmus to red, and react with bases
to form salts.
• BASE - A class of compounds that taste bitter, feel
slippery in water solution, turn red litmus to blue, and
react with acids to form salts.
• NEUTRAL - These are items that are neither acids or
There are 4 main ways to determine if a substance is and
acid or a base. They are: Red litmus paper, Blue litmus
paper, pH, and Red Cabbage Juice.
• There are 3 common acid-base theories: the Arrhenius
theory, the Bronsted-Lowry theory, and the Lewis
• The body is a sea of acids and bases.
• DNA is an acid based on Bronsted’s definition of an
1. ______ _____ in the 1660s, discovered that certain plant extract
could be used to distinguish between acids and bases.
2. Name an example of an acid that was mentioned on one of the
3. Name an example of a base that was mentioned on one of the
4. The three common acid-base theories are the Lewis theory,
________ theory, and the Bronsted-Lowery theory.
5. True or False. DNA is a weak acid, and it is weaker than
1. Robert Boyle
2. Vinegar, Lemon Juice, Soft Drink, Battery Acid, Stomach
Acid, Apple Juice, or Black Tea.
3. Detergent, Baking Soda, Drain Cleaner, Ammonia, Soaps
(hand, dish), or Antacid.
5. False. It is stronger that phosphoric acid.