Science 10Mrs. Knowles

Chapter 5.1: Acids, bases, and pH scale

pH scale:

Number scale for measuring ______________________________ __________________________________________________.

**no units

Acids: have a pH _________________________________Most acidic=

Examples:

Science 10Mrs. Knowles

Bases: have a pH _________________________________Most basic=

Examples:

Neutral substances have a pH of ________

Example

**Each number on the pH scale equals a ___________________ change in acidity / basicity

Example: If the pH changes from 1 to 2, this represents a _______ times change in degree of acidity/basicity.

If the pH changes from 14 to 10, this represents a ______ times change in the degree of acidity/basicity.

pH indicators: chemicals that change color depending on the ____ of the solution they are in.

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1) Methyl orange Color change happens at __________ pH Color changes from _____________ to _____________

as color increases

2) Methyl red Color change happens at __________ pH Color changes from _____________ to _____________

as color increases

3) Bromthymol blue Color change happens at __________ pH Color changes from _____________ to _____________

as color increases

4) Litmus paper: Color change happens at __________ pH Color changes from _____________ to _____________

as color increases

5) Phenolphthalein: Color change happens at __________ pH Color changes from _____________ to _____________

as color increases

6) Indigo carmine Color change happens at __________ pH

Science 10Mrs. Knowles

Color changes from _____________ to _____________ as color increases

**Reading check page 225**

Acids

From a chemical formula, how can you tell that something is an acid?

Often have an ________ added on to one side of the chemical formula.

They are ionic compounds where the cation is always _______.

When dissolved in water, acids produce _________.

Ex.

Cl

CH3COO

Naming acids:

1) If there is no oxygen in the anion (negatively charged ion)Add prefix hyrdo- and suffix -ic to the anion

Ex. HCl chlorine

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HCN cyanide

2) If there is oxygen in the anion

Case A: Polyatomic anion ends with -ate

= change to -ic

Case B: Polyatomic anion ends with –ite

=change to -ous

Examples:

HNO3

HNO2

**reading check: page 227: 1, 3, 4, 5

Science 10Mrs. Knowles

Bases

How can you tell something is a base by its chemical formula?

**Because ______ is written on the right side of the formula

Examples:

Production of Ions:

Acids produce ______ ions in water

Bases produce ______ ions in water

pH actually measures the amount of ______

-high concentration of H+ =

-low concentration of H+ =

Science 10Mrs. Knowles

Neutralization:

**Page 233: 4, 6, 7, 8, 13, 14

Science 10Mrs. Knowles

Science 10Mrs. Knowles

Science 10Mrs. Knowles

Science 10Mrs. Knowles