Acids & bases

Acids & bases

• 1.
  Acids & Bases
• 2.
  Acids ◦ Pre-caution ◦ Manyfluids we use are acids or bases however they do not injure us. ◦ Too strong of an acid or a base can cause serious injury. ◦ Always be cautious when working with either substance.
• 3.
  Acids ◦ pH <7 ◦A substance that are soluble (dissolves) in water and increases the hydrogen ion concentration of the solution. ◦ Taste sour and have a "stinging" feeling (like oranges, green apples, and rhubarb) ◦ Can dissolve metals. ◦ Contribute to environmental issues like acid rain. ◦ Strong acids pH < 2
• 4.
  Acid Videos
• 5.
  Bases ◦ pH >7 ◦A substance that is soluble (dissolves) in water to produce more hydroxyl ions (OH) than hydrogen ions (H). ◦ Taste bitter and feel slippery. ◦ An advantage to base cleaners: they do not react with metals. The cleaners used to unclog sinks are strong bases that readily dissolve hair and grease, but leave the pipes unscathed. ◦ Strong Base pH > 12
• 6.
  Neutral Substances ◦ NeutralSubstance (pH=7) ◦ example: distilled water.
• 7.
  pH ◦ pH ("powerof hydrogen") ◦ A measure of the concentration of hydrogen ions in the solution. ◦ Measure of how acidic or basic a substance is. ◦ Scale of 0-14; 0 is the most acidic, 14 is the most basic. ◦ A pH of 3 is 10X more acidic than a pH of 4. ◦ A pH of 9 is 10X more basic than a pH of 8.
• 8.
  pH ◦ To measurepH, use a pH scale or indicators (litmus paper and universal indicator) ◦ litmus paper: turns blue for base, red for acid. ◦ universal indicator: turns a different color for each number on the pH scale.
• 9.
  Neutralization ◦ Neutralization: Abase and an acid react to form a salt and water. ◦ Acid + Base -> Salt + Water ◦ Example: HCl + NaOH -> NaCl + H20 ◦ The products are less harmful than the reactants.
• 10.
  Neutralization ◦ Strong Acid+ Strong Base = Neutral ◦ Weak Acid + Strong Base = Basic ◦ Strong Acid + Weak Base = Acidic ◦ Weak Acid + Weak Base = Neutral/Acidic/Basic
• 11.
  Acid Rain Acid Rain:Rainwater with a lower than normal pH (<5.6). ◦ "Normal" rain is slightly acidic, because it contains dissolved carbon dioxide, and forms a weak carbonic acid. ◦ The rain becomes more acidic when water molecules react with other gases in the air, usually sulfur dioxide and several forms of nitrogen oxides. These gases are created by industrial factories, coal- fired power plants, and vehicle emissions. So acid rain is actually a mixture of weak carbonic, sulphuric, and nitric acids. ◦ Sometimes lime (calcium hydroxide) is used to neutralize lakes.