Acids and Bases

Acids• When acids dissolve in water, they ionize

(form ions).• When acids ionize, they form H+ ions.• These H+ ions give acids their properties

HCl = H+ Cl-

Cl- H+ Cl- Cl- H+

Characteristics of Acids• Acids tend to taste sour.

• Think of several examples of acids.

• Lemons, oranges, grapes, grapefruit, vinegar.

• These foods taste sour because they contain acids.

Characteristics of Acids

• Acids are corrosive. This means it can damage your skin and other materials.

• Acids also can conduct electricity.

• Acids cause pH (litmus) paper to turn red, orange, or yellow.

Characteristics of Acids

Based on the table above, what pH do acids have?pH of below 7What does the pH scale actually measure?It measures the amount of H+ ions.The closer the pH is to zero, the more H+ ions it contains.

Bases• When bases dissolve in water, they ionize

(form ions).• When bases ionize, they form OH- ions.• These OH- ions give bases their properties

NaOH =Na+ OH- Na+

OH- Na+ Na+ OH-

Characteristics of Bases• Base tend to taste bitter. (Do not taste these

yourself!!!!!!)• Think of several examples of bases.• Soap, bleach, ammonia, drano, glass cleaner.• What do all those substances have in common?• They are all cleaning agents!

Characteristics of Bases• Bases are just as dangerous as

bases. This means it can damage your skin and other materials.

• Bases also can conduct electricity.

• Bases cause pH (litmus) paper to turn green-blue, blue, and violet.

Characteristics of Bases

Based on the table above, what pH do bases have?pH above 7This means bases have fewer H+ ions and more OH+

ions.

Bases react with phenolphthalein

• Phenolphthalein reacts with substances that have a pH higher than 7.

• When it comes in contact with a base, it turn magenta, bright pink!!!!!

• When it comes in contact with an acid, it stay clear.

What is a substance has a pH of exactly 7?

• Water has a pH of exactly 7.Is water an acid or base? Neither, since it is exactly 7. Water is described as a

neutral substance.

What happens if you mix an acid and base together.

• You get a neutralization reaction if you mix an acid and base together.

• HCl + NaOH NaCl + H2O

The end result is a salt and WATER!!!!!!!This is why we call it a neutralization reaction! You get neutral water after the reaction!!!!