Mr. Bouyer

Day 1 | Day 2 | Day 3 | Lab | Vocabulary Test         9 weeks test review

Acid Hydronium ion Binary acid Ternary acid Base	Hydroxide ion pH scale Neutral Indicator Litmus	Phenolphthalein Neutralization Titration Salt Solubility Rules

Acids, Bases, and Salts

What element is written first in the formula of all acids?

Acid properties:

Acids produce the hydronium ion, H₃O ⁺ in solution.
Acids donate protons in chemical reaction.
• Remember that chemical reactions do not involve the atomic nucleus.
• When the electron is removed from hydrogen, making a hydrogen ion, the particle that remains is a proton.
Acids taste sour.
• The sour taste of citrus fruits is caused by citric acid.
• Never taste acids in the science lab!
Common acids contain hydrogen that is ionized in aqueous (water) solution.

Whether an acid is strong or weak depends on the amount of hydrogen ionized.

Binary acids -
• Composed of two elements, hydrogen and a nonmetal.
• Named with the prefix hydro, the name of the nonmetal, and the suffix ic.

Ternary acids -

• Composed of three elements, hydrogen, a nonmetal, and oxygen.
• The root name is the nonmetal name with the suffix ic.
• Prefixes and suffixes are used to indicate the amount of oxygen in the acid.

Some common acids:

HCl - Hydrochloric acid (strong)
HNO₃ - Nitric Acid (strong)
H₂SO₄ - Sulfuric acid (strong)
HC₂H₃O₂ - Acetic acid (weak)
H₃C₆H₅O₇ - Citric acid (weak)

Base properties:

Bases produce the hydroxide ion, OH ^- in solution.
Bases accept protons in chemical reaction.
Bases taste bitter. Don't taste bases in the science lab either!
Common bases contain the hydroxide ion that is ionized in aqueous solution.

Whether a base is strong or weak depends on the amount of hydroxide ion ionized.

Naming bases:

Almost all bases are composed of a metal and the hydroxide ion.
Name the metal first, the the word "hydroxide".

Some common bases:

NaOH - Sodium hydroxide (strong)
Ca(OH)₂ - Calcium hydroxide (strong)
Mg(OH)₂ - Magnesium hydroxide (strong)
NH₄OH - Ammonium hydroxide (strong)
Al(OH)₃ - Aluminum hydroxide (weak)

Homework Assignment 171:
This assignment must be turned in by the beginning of class tomorrow to receive credit.
Scoring criteria

1. Give the appropriate name or formula for the following acids.
   1. Hydroiodic Acid
   2. HF
   3. Hydrobromic Acid
   4. Nitric Acid
   5. H₂SO₄
2. Give the appropriate name or formula for the following bases.
   1. Sodium Hydroxide
   2. Ba(OH)₂
   3. Fe(OH)₃
   4. Copper (II) Hydroxide
   5. Tin (IV) Hydroxide
3. Write the formula for two binary acids.
4. Write the formula for two ternary acids.

Day 2

What color is phenolphthalein in a basic solution?

pH is a measure of the H₃O ⁺ concentration.

Compounds that show a color change in an acid or base.
Most indicators are weak organic acids or bases that react with ions in solution. It is this chemical reaction that produces the color change.
Indicators are used to determine the approximate pH of a substance.

Two common indicators are: Litmus - Acids turn blue litmus red. Bases turn red litmus blue. Phenolphthalein - Colorless in an acid. Very faint pink in a neutral solution. Bright pink in a base.

pH Meter: A device used to measure the exact pH of a solution.

Test Your Concept Understanding: What is the chemical formula for the hydronium ion? What is the chemical formula for the hydroxide ion? What is the pH of a solution that has an equal amount of hydroxide and hydronium ions? Which is the stronger acid, one with a pH of 2 or one with a pH of 6? Which is the weaker base, one with a pH of 8 or one with a pH of 12? Use a SHS Chemistry Class webpage to find the pH of the following: blood coffee milk oven cleaner cola drinks

Ask your science facilitator for the material to make an acid / base indicator. Do the following: Finely chop half a head of red cabbage. Carefully boil the cabbage in a liter of water for 5 minutes. Remove from heat and let stand until completely cool. Strain the liquid, and throw away the used cabbage. The liquid should be a dark reddish purple color. Describe the color change when several drops of your indicator are added to the following: A colorless acid solution. A colorless base solution. A colorless neutral solution.

Day 3

What is a precipitate?

Chemical Sales Representative

Neutralization - the reaction of an acid with a base to form a salt and water.

HCl  +  NaOH    NaCl  +  H₂O

Acid/base neutralization is accomplished in the lab by a process known as titration.

Salts - composed of the positive half of a base and the negative half of an acid.

Question:   What acid and base react to produce each of these salts?

CaSO₄       NH₄NO₃       CaCl₂       

Precipitate - an insoluble substance that crystallizes out of solution.

H₂CO_3(aq) + Mg(OH)_2(aq) MgCO_3(cr) + 2H₂O_(l)

The red symbols in the above equation tell you the physical state of the substance. They tell you if a solid is dissolved or not. These symbols are not always shown in equations, but are helpful when they are. aq - aqueous, the substance is dissolved in water solution. cr - crystal solid s - solid l - liquid g - gas

In-class Assignment 173:
This assignment must be turned in by the end of class today to receive credit.
Scoring criteria

1. Write the balanced equation for the neutralization of sulfuric acid with sodium hydroxide.
2. What is the name of the salt produced in question #1?
3. Is this salt produced in question #1 soluble in water?
   These solubility rules will tell you.
4. Rewrite your equation from question #1 adding the appropriate physical state symbols shown on this page.
5. What acid and base are used to produce CaNO₃?

Physical Science

  Answers:

CaSO₄ . . . . . . . . Ca(OH)₂ + H₂SO₄
Calcium Sulfate is produced from Calcium Hydroxide and Sulfuric Acid.

NH₄NO₃ . . . . . . . . . . NH₄OH + HNO₃
Ammonium Nitrate is produced from Ammonium Hydroxide and Nitric Acid.

CaCl . . . . . . . . . . . Ca(OH)₂ + HCl
Calcium Chloride is produced from Calcium Hydroxide and Hydrochloric Acid.

Hydrogen is always the first element written in the formula of an acid.

Phenolphthalein is an acid-base indicator that is pink in a base and colorless in an acid.

A precipitate is an insoluble substance that crystallizes out of solution.