1. Section 2.4—Defining, Naming & Writing Acids & Bases
We need to know what acids behave when talking about ant-acids!

2. Acids

3. Acids – Arrhenius Definition
Produce Hydronium ion (H3O+1) in water
Hydronium ion is water + a hydrogen cation H O
water H O +1 H +1
By this definition, if an acid is to give a H+1 to water, then all acids will have hydrogen as the cation (first element written).

4. How do Acids produce Hydronium?-
water
acid
Hydrogen cation with some anion

5. How do Acids produce Hydronium?- +1 H O

6. How do Acids produce Hydronium?- +1 H O
Hydronium ion
Anion

7. Naming Acids

8. Naming non-oxygen Acids
These compounds have:
Start with “H” (more than 1 “H” is OK, too).
Do not contain oxygen
To name these compounds:
Use “hydro____ic acid”
Fill in the blank with the anion’s name without the last syllable

9. Example #1
HBr

10. HBr Example #1 Hydrobromic acid Hydrogen cation Bromine It’s an acid
No oxygen
Use “hydro___ic”

11. Naming Oxygen Acids These compounds have: To name these compounds:
Start with “H” (more than 1 “H” is OK, too).
Do contain oxygen
To name these compounds:
Use “___ic acids” for “-ate” anions
Use “___ous acids” for “-ite” anions
Do not use “hydro” with these…the word “acid” is how you know it begins with hydrogen, not “hydro-”

12. Example #2
H2SO3

13. H2SO3 Example #2 Sulfurous acid Hydrogen cation Sulfite ion
It’s an acid
Hydrogen cation
H2SO3
Sulfite ion
“-ite” ion
Use “___ous” acid
Sulfurous acid

14. Example #3
H2SO4

15. H2SO4 Example #3 Sulfuric acid Hydrogen cation Sulfate ion
It’s an acid
Hydrogen cation
H2SO4
Sulfate ion
“-ate” ion
Use “___ic”
Sulfuric acid

16. Write the name for the following compounds
Let’s Practice
HCl
HNO3
H2S
H3PO3
Example:
Write the name for the following compounds

17. Write the name for the following compounds
Let’s Practice
HCl
HNO3
H2S
H3PO3
Hydrochloric acid
Nitric acid
Hydrosulfuric acid
Phosphorous acid
Example:
Write the name for the following compounds

18. Writing Acid Formulas

19. “Hydro-” acids To write these formulas: The cation is H+1
Write the anion and charge
Balance the charges by adding the appropriate subscript to the hydrogen cation

20. Example #4
Hydrofluoric acid

21. Does not contain oxygen
Example #4
H+1
Hydrogen cation
Hydrofluoric acid
Does not contain oxygen
F-1

22. Does not contain oxygen
Example #4
H+1
Hydrogen cation
Hydrofluoric acid
Does not contain oxygen
H+1F-1
F-1
= 0 HF
The compound is neutral.
Subscripts are not needed

23. NON “Hydro-” acids To write these formulas: The cation is H+1
If it is an “-ic” acid, the anion is the “-ate” polyatomic ion
If it is an “-ous” acid, the anion is the “-ite” polyatomic ion
Add subscript to the hydrogen cation to balance charges

24. Example #5
Carbonic acid

25. From the “___ate” anion
Example #5
H+1
Hydrogen cation
Carbonic acid
From the “___ate” anion
CO3-2

26. From the “___ate” anion
Example #5
H+1
Hydrogen cation
H+CO32-
= -1
Carbonic acid
H+H+CO32-
= 0
From the “___ate” anion
CO3-2
H2CO3

27. Example #6
Nitrous acid

28. From the “___ite” anion
Example #6
H+1
Hydrogen cation
Nitrous acid
From the “___ite” anion
NO3-1

29. From the “___ite” anion
Example #6
H+1
Hydrogen cation
Nitrous acid
H+NO2-
From the “___ite” anion
= 0
NO3-1
HNO2

30. Write the formula for the following acids
Let’s Practice
Phosphoric acid
Hydroiodic acid
Carbonous acid
Perchloric acid
Example:
Write the formula for the following acids

31. Write the formula for the following acids
Let’s Practice
Phosphoric acid
Hydroiodic acid
Carbonous acid
Perchloric acid
H3PO4 HI
H2CO2
HClO4
Example:
Write the formula for the following acids

32. Bases

33. Bases – Arrhenius Definition
Bases produce the hydroxide ion in water H O -1
Hydroxide Ion

34. Naming & Writing Bases

35. Naming Bases
Most bases are just ionic compounds with “hydroxide” as their anion
The most common exception to this is ammonia
NH3 (ammonia) is a base even though it doesn’t contain “-OH” as the anion

36. Example #7
NaOH

37. Example #7
Sodium
NaOH
Sodium Hydroxide
Hydroxide

38. Write the formula or name for each
Let’s Practice
Ca(OH)2
KOH
Sr(OH)2
Copper (II) hydroxide
Magnesium hydroxide
Example:
Write the formula or name for each

39. Write the formula or name for each
Let’s Practice
Ca(OH)2
KOH
Sr(OH)2
Copper (II) hydroxide
Magnesium hydroxide
Calcium hydroxide
Potassium hydroxide
Strontium hydroxide
Cu(OH)2
Mg(OH)2
Example:
Write the formula or name for each