1. QOTD 5/14/14 Please have out to be checked off: Soap reading/prelab Qs
p. 59 Qs
QOTD: Rank the following solutions in order of most acidic to least acidic and explain why.
1 M vinegar (weak acid)
1 M HCl (strong acid)
0.5 M HCl (strong acid)
1 M NaOH (strong base)
1 M NH3 (weak base)
Pure water

2. QOTD Answer
QOTD: Rank the following solutions in order of most acidic to least acidic and explain why.
1 M HCl (strong acid) % ions (excess H+)
0.5 M HCl (strong acid) % ions (excess H+)
1 M vinegar (weak acid) less than 100% ions (~1%)
Pure water neutral
1 M NH3 (weak base) less basic than a strong base
1 M NaOH (strong base) strong base = most basic = least acidic

3. Answers Homework Qs! (p. 59)

4. The 1.0 M HCl because it dissociates completely…more H+ means lower pH
Check-in Questions:
1. You have a 1.0 M solution of a strong acid (HCl) and 1.0 M of a weak acid (acetic acid). Predict which will have a lower pH, and explain why:
The 1.0 M HCl because it dissociates completely…more H+ means lower pH

5. Check-in Questions:
2. How is the Bronsted-Lowry definition of acid/base theory different from Arrhenius?
The Bronsted-Lowry theory says that a base can accept a proton (H+) (in addition to donating a OH-).

6. Homework Questions:
1. Label the following substances as acids or bases. In each case, list the ions you would expect to form in solution:
a. Hydroiodic Acid, HI
b. Rubidium Hydroxide, RbOH
c. Selenous acid, H2SeO4
d. Phosphine, PH3
e. Calcium hydroxide, Ca(OH)2
f. Perchloric acid, HClO4
Acid, H+, I-
Base, Rb+, OH-
Acid, 2 H+, SeO42-
Base, PH4+, OH-
Base, Ca2+, 2 OH-
Acid, H+, ClO4-

7. 10 Br- ions (to cancel out the 10 H+ ions)
2. Consider a solution of hydrobromic acid, HBr. If you drew a particle view of HBr in water that contained 10 H+ ions, how many Br- ions would you need? Explain your thinking:
10 Br- ions (to cancel out the 10 H+ ions)
3. Consider a solution of mangnesium hydroxide, Mg(OH)2. If you drew a particle view of this substance with 10 Mg2+ ions, how many hydroxide (OH- ) ions would you need to draw?
20 OH- ions
4. The CO32- ion is a weak base. Explain, using Bronsted-Lowry theory, what makes this substance a base:
It can accept a proton (H+)

8. Challenge: Some solutions conduct electricity better than other solutions. Use your knowledge about the different kinds of acids and bases to explain why a 1.0 M hydrochloric acid solution is a better conductor of electricity than a 1.0 M acetic acid solution.
The strong acid dissociates completely, making it easier for electricity to flow through the solution . (more ions = more moving charges)

9. PLEASE SEND A GROUP MEMBER TO GRAB NOTES SHEETS!
Acids and Bases Notes
PLEASE SEND A GROUP MEMBER TO GRAB NOTES SHEETS!

10. Arrhenius Theory
Acid: A substance that adds hydrogen ions, H+, to an aqueous solution
Base: A substance that adds hydroxide ions, OH-, to an aqueous solution
Not the best definition…

11. Bronsted-Lowry Definition
Acid: Any chemical that donates a hydrogen ion, H+
Base: Any chemical that accepts a hydrogen ion into their structure +
Base
Acid
Proton acceptor
Proton donor

12. BAAD Bases Accept, Acids Donate Example: HCl + H2O  Cl- + H3O+
NH3 + H2O  NH4+ + OH-
Acid
Base H+
Acid
Base H+

13. Other terms to know Hydronium ion: H3O+ Hydroxide ion: OH-
Amphoteric (or amphiprotic) : Water can act as both an acid and a base in different situations

14. Your Turn (partner talk)
H2O + HBr  Br- + H3O+ Which compound is acting as an acid? Which is acting like a base?
HBr
H2O

15. Your Turn (Partner talk)
H2O + SO42-  OH- + HSO4- Which of the compounds is acting as a base?
SO42-

16. Your Turn (partner talk)
Predict the products when phosphoric acid (H3PO4) is added to water:
H3PO4 + H2O  H2PO4- + H3O+

17. Properties of Acids Corrosive Sour taste
Contains hydrogen ions (H+) when dissolved in water
pH < 7
Electrolytes (conduct electricity)
Neutralize bases

18. Examples of Acids Hydrochloric acid (HCl) in gastric juice
Sulphuric acid (H2SO4)
Nitric acid (HNO3)
Carbonic acid in soft drinks (H2CO3)
Uric acid in urine
Ascorbic acid (Vitamin C) in fruit
Citric acid in oranges and lemons
Acetic acid in vinegar

19. Properties of Bases Taste bitter Slippery
Electrolytes (conduct electricity)
Base + fat = soap
Neutralize acids
Corrosive

20. Examples of Bases Sodium hydroxide (NaOH)
Calcium hydroxide ( Ca(OH)2 ) or limewater
Ammonium hydroxide (NH4OH) or ammonia water
Magnesium hydroxide ( Mg(OH)2 ) or milk of magnesia
Many bleaches, soaps, toothpastes and cleaning agents

21. Indicators
Substances that change color when exposed to an acid or base
Can be used to identify acids and bases, even their strength
Usually a weak acid or base

22. Examples of indicators
Litmus paper: Red for acid, blue for base
pH paper: universal indicator, compare colors to known pH
Cabbage juice: color changes in response to concentration of H+ ions
Phenolphthalein: color is clear/cloudy in an acid and pink in a base

23. Solutions
Acidic solution: the hydronium ion concentration is higher than the hydroxide ion concentration [H+] > [OH-]
Basic solution: hydroxide ion concentration is higher than the hydronium ion concentration
[H+] < [OH-]

24. Neutral solution: concentration of hydronium and hydroxide ions is the same
[H+] = [OH-]
Ex. Pure water
Created when equal quantities of an acid and base are combined

25. pH 7 14 pH: Measures the concentration of H3O+ ions
pH scale: A numeric scale used to describe the acidity of a solution from 0 to 14
Draw the scale below 7 14
Increasing strength
Increasing strength
Acids
Neutral
(water)
Bases

26. pH Scale Acidic Neutral solution Basic

27. Strong vs. Weak Acids and Bases
Strong Acid or Base: all of the molecules dissociate (split apart) into ions
Weak Acid or Base: Only some of the molecules actually dissociate
Not as many H+ or OH- ions in solution

28. Strong base
Weak base

29. Soap! Let’s review the soap procedure…
SAFETY! What will you use to protect yourself?
GOGGLES FOR EVERYONE!
Gloves for the person who pours the NaOH and mixes it.
How hot will you make the NaOH and Oils?
50 degrees! They both need to be around 50 (+ or – a couple degrees)