1. Acids, Bases and Reaction Rates
Unit 14
Acids, Bases and Reaction Rates

2. Acids and Bases
And others…

3. Acids
For thousands of years people have known that vinegar, lemon juice and many other foods taste sour.
However, it was not until a few hundred years ago that it was discovered why these things taste sour – They taste sour because they are all acids.
The term acid, in fact, comes from the Latin term acere, which means "sour"

4. Acid Characteristics Acids have a PH of less than 7. Acids taste sour
Acids are corrosive to metals
Acids can ‘burn' your skin
Acids change litmus paper red
Litmus paper helps to determine acids and bases
Acids become less acidic when mixed with bases.

5. Examples of Acids
orange juice, lime juice or lemon juice (citric acid)
vinegar (acetic acid)
aspirin (salicylic acid)
yogurt (lactic acid)
Coca-Cola (phosphoric acid)
toilet bowl cleaner (sulfuric acid)
bathroom cleaner (muriatic acid)
wine (tartaric acid and/or malic acid)
vitamin C tablets (ascorbic acid)
urine (uric acid)

6. Bases Bases can also be called alkalis.
Bases can be thought of as the chemical opposite of acids.
A reaction between an acid and base is called neutralization
We will talk more about this tomorrow
An example of base: soap

7. Base Characteristics Bases have a pH more than 7 Bases feel slippery
Converts fats and oils in skin to glycerin (slick feel)
In a sense, bases dissolve your skin… think of getting Clorox bleach on your skin
Bases turns litmus paper to a blue color.
Bases become less basic when mixed with acids.
Bases reacts with acids to form salt and water

8. Base Examples Mustards Many medicines
Ie. Magnesium oxide – treats indigestion
Bleaches, soaps, toothpastes, window cleaners and other cleaning agents
Sodium Hydrogen Carbonate (bread soda).
Sodium hydroxide (NaOH) or caustic soda
Calcium hydroxide ( Ca(OH)2 ) or limewater
Ammonium hydroxide (NH4OH) or ammonia water
Magnesium hydroxide ( Mg(OH)2 ) or milk of magnesia

9. pH Scale Measure of how acidic or how basic More Acidic More Basic
Pure water
Baking Soda
Stomach Acid
Egg Whites
Mineral Lime
Vinegar
Rain
NaOH
HCl
Lemon Juice
Ammonia
Drano
Soda
Tums
More Acidic
More Basic

10. ACIDS
1 - HCL
2 – Stomach Acid
3 – Lemon Juice
4 - Vinegar
5 - Soda
6 – Rain Water
BASES
8 – Egg Whites
9 – Baking Soda
10 - Tums
11 - Ammonia
12 – Mineral Lime
13 - Drano
14 - NaOH
Neutral:
7 – Pure Water

11. Acids and Bases… and others
Identification

12. Identifying Acids
Acids start with “H”
Examples:
HCl
H2SO4

13. Identifying Bases Bases end in “OH” (hydroxides) Examples: NaOH
Ca(OH)2

14. Identifying Metals
Metals are single elements found on the left side of the periodic table
Separated from non-metals by metalloids (staircase)
Examples Al Li
Can you name any other ones?

15. Identifying Carbonates
Carbonates end with the elements “CO3”
Examples
Na2CO3
MgCO3

16. Identifying Salts
Salts are two elements bonded together from opposite sides of the periodic table or with a polyatomic ion
What is polyatomic ions?
Examples
NaCl
AlF3
KNO3

17. Reactions with Acids

18. Let’s Review… How do we know which chemicals are… Bases? Acids?
Carbonates?
Salts?
Metals?

19. Let’s practice~ Classify the following chemicals…
NaCl HCl Li2CO3
Mg KOH Ag
MgCO3 BeF2 Al(OH)3
Groups:
Metals Acid Bases Carbonates Salts
Metals – Ag, Mg
Acids – HCl
Base – Al (OH)3, KOH
Carbonates – Li2CO3, MgCO3
Salts – NaCla, BeF2

20. Review – Charges on Ions
Group
(Periodic Table)
Example
Charge
Why?
Alkali metal
Alkaline earth metal
Nitrogen group
Chalcogens
Halogens
Alkali metals +1 (loses 1 electron so have full outer orbital)
Alkaline earth metals +2 (loses 2 electrons so have full outer orbital)
Nitrogen group -3 (gains 3 electron so have full outer orbital)
Chalcogens -2 (gains 2 electron so have full outer orbital)
Halogens -1 (gains 1 electron so have full outer orbital)

21. Review Writing Formulas
Let’s practice:
Lithium iodide
Magnesium hydroxide
Hydrogen gas
Sodium
Calcium carbonate
Li +1, I -1  LiI
Mg +2, OH -1  Mg(OH)2
H  H2
Na (not in compound = no charge, not an ion)
Ca +2, CO3 -2  Ca2(CO3)2 , but if both 2s  CaCO3

22. Review Balancing Equations
___ NaNO3 + ___ PbO  ___ Pb(NO3)2 + ___ Na2O
___ AgI + ___ Fe2(CO3)3  ___ FeI3 + ___ Ag2CO­3

23. ACIDS REACT WITH METALS
Acid is a compound, metal is an element…
So what type of reaction?
HCl Li  _________ + __________
HF Mg  _________ + _________
H2S + Al  _________ + _________
Therefore…
Acid Metal  salt H2
What type of reaction involves a compound and an element? - single displacement
-what side of the periodic table is the metal on? Left (positive)
-therefore the metal will displace the element on the left of the (the positive element)– so will displace the hydrogen out of the compound to produce salt and H2 gas
HCl + Li  LiCl +H2
HF + Mg  MgF2 + H2 (need to criss cross)
H2S + Al  Al2S3 + H2 (need to criss cross)
**DON’T FORGET TO BALANCE!!!

24. Acid + Carbonate  salt + CO2 + H2O
ACIDS WITH CARBONATES
Acid is a compound, carbonate is an compound…
So what type of reaction?
HCl MgCO3 ________ + _________
HI Li2CO3  ________ + ________
H2S + Na2CO3  _______ + _________
Acid + Carbonate  salt + CO2 + H2O
What type of reaction involves two compound? - double displacement
-positives switch
H2CO3  very reactive, breaks down almost immediately into H2O and CO2
HCl + MgCO3  MgCl2 + H2CO3 MgCl2 + CO2 + H2O
HI + Li2CO3  LiI + H2CO3  LiI + CO2 + H2O
H2S + Na2CO3  Na2S + H2CO3  Na2S + CO2 + H2O
**DON’T FORGET TO BALANCE EQUATIONS!!

25. Acid and Base Reactions

26. ACIDS and BASES REACTIONS
What distinguishes acids?
What distinguishes bases?

27. ACIDS and BASES Acid is a compound, base is an compound…
So what type of reaction?
__ HCl + __ NaOH  __ NaCl + __ HOH
H2O
__ HF + __ Ca(OH)2  __Ca F2 + __ H2O
Acid + Base  salt + H2O

28. Titration Neutralizing an acid or base MA x VA = MB x VB M = molarity
V = volume
A = acid
B = base

29. Practice
If you add 10mL of acid to 20mL of a .10M basic solution, what will the molarity of the acid be?
MA x VA = MB x VB
Lets look at volume and molarity…
Less concentrated, we need more
More concentrated, we need less