Strengths of Acids and Bases

Strengths of Acids and Bases

Benchmark: SC.912.P.8.11

Student objective:

• Use experimental data to illustrate and explain the pH scale to characterize acid and base solutions;

• Compare and contrast the strengths of various common acids and bases;

• Measure pH using various tools; for example, litmus paper pH indicators and pH probe

Multiple Choice

A(n) _____ is a substance that produces hydrogen ions in solution.

• base

• acid

• indicator

• salt

Multiple Choice

Which of the following statements about acids is NOT true?

• acids taste sour

• acids are corrosive

• acids form hydroxide ions in a solution

• many foods contain acids

Multiple Choice

A(n) ______ is an organic compound that changes color in acid.

• catalyst

• base

• indicator

• salt

Multiple Choice

Any substance that forms hydroxide ions in solution is a(n) ______.

• acid

• salt

• indicator

• base

Multiple Choice

Which of the following statements about bases is NOT true?

• Pure, undissolved bases are often crystalline solids.

• bases form when acids react with metals

• bases in solution feel slippery

• bases form hydroxide ions in solution

Open Ended

In yesterday's lab, we discussed and tested the pH levels of different substances. Give three examples of substances that are acidic and basic. Then explain what characteristics make those substances acidic or basic.

Reminder:
- pH is a measurement that is used to rate the strengths of acids and bases, indicating positive hydrogen ions or H+ ions.

Scenario: A swimming pool and spa owners must find out whether the water is too acidic or basic.

​Turn and Talk - Why is it important for these owners to have the proper pH?

1. What determines the strength of an acid or a base?
2. How effectively do different acids and bases conduct electricity?
3. What is the difference between strength and concentration?

​Today's Essential Questions

​Important vocabulary to know:
Ionization - the process in which some molecules dissolve in water and separate into charged particles.

• Depends on the degree to which acid or base particles form into ions in water

• Strong acids ionize upon dissolving in water.

• In weak acids, a small fraction of ionization occurs in water.

Determining the Strength of an Acid

• Ions in a solution conduct electric currents.

• More ions = More conductivity

• Less ions = Less conductivity

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Effectiveness of acids and bases when conducting electricity.

Multiple Choice

A _____ will ionize only to a small extent because its molecules have a strong hold on their H atoms.

• weak acid

• strong acid

• weak base

• strong base

Group Discussion Question

What do you think is the difference between the terms strength and concentration?

Strength vs. Concentration

Remember: Strength refers to the degree to which an acid or base ions are formed in water.

Concentration - refers to how much acid or base is present in a solution.

Go to Google classroom and complete the strengths of acids and bases reinforcement.

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Today's Activity

Open Ended

Based on today's lesson, what did you learn today? What did you like or dislike about today's lesson?