Acids, Bases and pH

ACIDS Acids are substances that donate Hydrogen ions (H + ) to form hydronium ions (H 3 O + ) when dissolved in water. Acids are substances that donate Hydrogen ions (H + ) to form hydronium ions (H 3 O + ) when dissolved in water. HCl + H 2 O H 3 O + + Cl - HCl + H 2 O H 3 O + + Cl - hydrocloric acidHydronium ion hydrocloric acidHydronium ion Acids can conduct electricity when dissolved in water because they create ions. Acids can conduct electricity when dissolved in water because they create ions. Sulfuric acid and water conduct electricity in car batteries. Sulfuric acid and water conduct electricity in car batteries. Strong acids completely ionize in water.Strong acids completely ionize in water. Ionize means to create ions when dissolved in solution.Ionize means to create ions when dissolved in solution. Weak acids do not conduct electricity very well because they do not completely ionize in water. Weak acids do not conduct electricity very well because they do not completely ionize in water. Turn litmus paper red. Turn litmus paper red.

Acids Acid solutions will have a greater number of H + ions than OH- ions. Acid solutions will have a greater number of H + ions than OH- ions. Acids are proton donors (H + ). Acids are proton donors (H + ). Strong acids contain hydrogen atoms bound to a non-metal or polyatomic ion. Strong acids contain hydrogen atoms bound to a non-metal or polyatomic ion. Example:Example: HCl, H 2 SO 4, HNO 3, H 3 PO 4 HCl, H 2 SO 4, HNO 3, H 3 PO 4 Some weak acids areSome weak acids are HCOOH (formic acid), C 6 H 8 O 7 (citric Acid), CH 3 COOH(acetic acid) HCOOH (formic acid), C 6 H 8 O 7 (citric Acid), CH 3 COOH(acetic acid)

BASES A base is a substance that either contains hydroxide ions (OH - ) or reacts with water to form hydroxide ions. A base is a substance that either contains hydroxide ions (OH - ) or reacts with water to form hydroxide ions. Feel slippery to the touch. Feel slippery to the touch. Turn litmus paper blue. Turn litmus paper blue. Strong Bases end in an OH and completely ionize in water to form OH - ions. Strong Bases end in an OH and completely ionize in water to form OH - ions. KOHK + + OH -KOHK + + OH - Potassium hydroxide is found in some drain cleaners.Potassium hydroxide is found in some drain cleaners. Strong bases conduct electricity well when dissolved in water.Strong bases conduct electricity well when dissolved in water.

BASES Other bases that do not contain OH - ions react with water to create OH - ions. Other bases that do not contain OH - ions react with water to create OH - ions. NH 3 + H 2 O H 3 O + + OH -NH 3 + H 2 O H 3 O + + OH - ammonia water hydronium ion hydroxide ion A solution with more OH - ions than H + ions is considered basic (alkaline)

pH and the pH Scale Ph indicators are substances that can determine whether a solution is acidic or basic. Ph indicators are substances that can determine whether a solution is acidic or basic. The scale spans from The scale spans from Each unit of pH represents a factor of 10 in the hydronium ion concentration.Each unit of pH represents a factor of 10 in the hydronium ion concentration. Stomach acid has a pH of 2 and is therefore 10 times more acidic than apple juice with a pH of 3.Stomach acid has a pH of 2 and is therefore 10 times more acidic than apple juice with a pH of 3.

Neutralization Reactions Strong acids and bases react together to produce salt water. Strong acids and bases react together to produce salt water. Remember strong acids completely ionize in water.Remember strong acids completely ionize in water. HCl + H 2 OH 3 O + + Cl - HCl + H 2 OH 3 O + + Cl - Strong bases completely ionize in water.Strong bases completely ionize in water. NaOH Na + + OH - NaOH Na + + OH - If the two solutions are mixed in equal amounts we get:If the two solutions are mixed in equal amounts we get: H 3 O + + Cl - + Na + + OH - Na + + Cl - + 2H 2 O

Neutralizing Reactions Acids and bases do not always neutralize each other. Acids and bases do not always neutralize each other. Depends on the strength and amount of each substance added.Depends on the strength and amount of each substance added. Buffers are substances that resist a change in pH. Buffers are substances that resist a change in pH. Common in living systems.Common in living systems. Often weak acids can act as buffers.Often weak acids can act as buffers. Carbonic acid either donates H + ions or absorbs them to keep blood from becoming too acidic or basic. Carbonic acid either donates H + ions or absorbs them to keep blood from becoming too acidic or basic.

Bases At Home Bases At Home Soaps are emulsifiers that let water and oil mix. Soaps are emulsifiers that let water and oil mix. Soaps bring out the grease in materials and allows them to be washed away with water.Soaps bring out the grease in materials and allows them to be washed away with water. Soaps are made by reacting vegetable oils or animal fats with a strong base (KOH or NaOH).Soaps are made by reacting vegetable oils or animal fats with a strong base (KOH or NaOH). Soaps are long hydrocarbon chains with a charged atom on the end. Soaps are long hydrocarbon chains with a charged atom on the end. The hydrocarbon chain reacts with the non-polar grease while the charged atom reacts with water because water is polar. The hydrocarbon chain reacts with the non-polar grease while the charged atom reacts with water because water is polar. Allows grease to be suspended in water. Allows grease to be suspended in water.

Bases At Home Ammonia solutions ionize in water to form an ammonium ion. Ammonia solutions ionize in water to form an ammonium ion. NH 3 + H 2 ONH OH - Ammoniaammonium ionhydroxide ion The hydroxide ion interacts with the grease to form an emulsion with water which lifts away when wiped.

Many Health Care Products are Acids or Bases Tums an antacids are basic to neutralize your stomach acids.Tums an antacids are basic to neutralize your stomach acids. Magnesium Hydroxide Mg(OH) 2 Magnesium Hydroxide Mg(OH) 2 Milk of MagnesiaMilk of Magnesia Aspirin is salicylic acid.Aspirin is salicylic acid. Shampoos are pH balanced because hair that is too basic has dull appearance.Shampoos are pH balanced because hair that is too basic has dull appearance. Shampoos usually have a pH’s between 5 and 8. Shampoos usually have a pH’s between 5 and 8.

Acids and Bases in the Kitchen Marinates usually have vinegar in them to denature proteins in meat and meat becomes more tender. Marinates usually have vinegar in them to denature proteins in meat and meat becomes more tender. Baking soda is basic (NaHCO 3 ) Baking soda is basic (NaHCO 3 ) Makes cakes fluffy and also absorbs odors in the fridge.Makes cakes fluffy and also absorbs odors in the fridge. Milk curdles because bacteria are converting the lactose in milk to acid. Process also creates yogurt and accounts for the tangy taste.Process also creates yogurt and accounts for the tangy taste.