Download - What is the volume of one mole of a gas at STP? Identify the pH associated with acids and bases
What is the volume of one mole of a gas at STP?
Identify the pH associated with acids and bases.
Give two ways that acids are different from bases that does
not include their pH.
1. pH < 7.0
2. Electrolytes
3. Taste Sour
4. React with bases to form H2O + Salt
5. React with metals to form H2(g) and salt
Table J
1. pH > 7.0
2. Electrolytes
3. Taste Bitter
4. React with acids to form H2O + Salt
5. Slippery, soapy feeling
Arrhenius gives off an H+ and forms H3O+
- increases the H+ when dissolved in water
Bronsted proton [H+] donor (loses an H+)
HCl
H+ + H2O
H+ + Cl-
H3O+
Arrhenius gives off an OH-
Bronsted proton [H+] acceptor (gains an H+)
NaOH
Ca(OH)2
Na+ + OH-
Ca+2 + OH-2
Chemicals which change colors when they are put into acids or bases.
These indicators change colors in response the [H+].
Table M
If you were to place H2SO4 onto a piece of copper, would it react to produce hydrogen gas? Explain your answer.
MAVA = MBVB
- Perform titrations to determine an unknown volume or concentration of an acid/base
- ENDPOINT = when indicator changes color
- Moles of H+ = Moles of OH-
- Products are always water and salt
MA= molarity of acid
VA= volume of acid
MB= molarity of base
VB= volume of base
MAVA = MBVB
If 20.0ml of a 0.50M HCl solution is needed to neutralize 65.0ml of a NaOH solution. What was the concentration of the base?
MA= molarity of acid
VA= volume of acid
MB= molarity of base
VB= volume of base
(0.5M)(20.0ml) = MB(65.0ml)
MB= 0.154M
MAVA = MBVB
43.0ml of HCl was titrated with 32.0 ml of 0.100 M NaOH. What is the molarity of the hydrochloric acid solution?
MA= molarity of acid
VA= volume of acid
MB= molarity of base
VB= volume of base
MA(43.0ml)=(0.100M)(32.0ml)
MA= 0.0744 M
Conjugate PairsConjugate Pairs
HCl + KOH HOH + KCl
acid base conj. acid conj. base
Na2CO3 + 2HCl
base acid conj. acid conj. base
conj. base conj. acidacidbase
Strong acids have weak conjugate bases
Weak acids have strong conjugate bases
H2O + H2SO4
H2CO3 + 2NaCl
HSO4- + H3O+
Identify the acid, base, conjugate acid, conjugate base, and conjugate acid-base pairs:
acid base conjugate acidconjugate baseHC2H3O2(aq) + H2O(l) C2H3O2
–(aq) + H3O+(aq)
conjugate acid-base pairs
acidbase conjugate acidconjugate baseOH
–(aq) + HCO3–(aq) CO3
2–(aq) + H2O(l)
conjugate acid-base pairs
Information related to an experiment is listed below:
H2SO4 + 2KOH K2SO4 + 2H2O
Results
Volume H2SO4 used 12.0 ml
Concentration H2SO4 ?
Volume KOH used 36.0 ml
Concentration KOH 0.16 M
Based on the above results, what is the concentration of H2SO4?
Setup for titrating an acid with a baseSetup for titrating an acid with a base
MAVA = MBVB
Calculate the molarity of an acetic acid solution if 34.57 mL of this solution are needed to neutralize 2.519 cL of 0.1025 M sodium hydroxide
MA= molarity of acid
VA= volume of acid
MB= molarity of base
VB= volume of base
(MA)(34.57ml) = (0.1025M)(25.19ml)
MA= 0.07469M
Trial 1
Trial 2
Trial 3
Avg
Final Acid Volume
Initial Acid Volume
Final Base Volume
Initial Base Volume
Volume of Acid Used
Volume of Base Used
What are electrolytes?
Give two examples.
46) 25 mL
47)3000 mL
48)20 mL
49)50.0 mL
50)6.0 M
51)0.60 M
52)400 mL
53)1.0 M
54)SKIP
55)
H Cl
56)
H O
H
H
+
57) O H
-
pH of Common pH of Common SubstancesSubstances
pH = -log[H+]
If [H+] = 1 x 10-4, then pH =
- a way to measure the concentration of H+ ions (H3O+) in a solution
- concentration of H+ = [H+]
4
If [H+] = 1 x 10-13, then pH = 13
If [H3O+] = 1 x 10-7, then pH = 7
What is the pH of a 0.00001 molar HCl solution?
If the pH of your pool is 6, what is the concentration of hydronium ions in solution?
As the pH of a solution is changed from 3 to 6, how does the concentration of hydronium ions change?
An aqueous solution that a [H+] of 1.0 x 10-8 mole per liter has a pH of?
• Because it is a logarithmic scale, each one unit change in pH really represents a 10 fold change in [H+]
• So going from a pH of 6 to 7 really represents a 10 fold decrease in the number of [H+]
What is the difference in [H+] in a pool that has a pH of 6, but in reality you want it to have a pH of 7?
If [OH] = 10-8 M, what is the pH?
[H+][OH-] = 10-14
pH + pOH = 14
Solution:
• the OH = 8, so the pH must be 14 – 8
• So the pH = 6
Solution A has a pH of 1 and solution Z has a pH of 5.
How many times greater is the hydronium ion
concentration in solution A?
-A compound that does not allow the pH to change even if an acid or base is added to the system
-They have the ability to absorb/release H+ which will keep the pH relatively constant
-Good buffers are amphiprotic substances
-Amphiprotic – something that can act as an acid and a base
-Blood pH
-Adirondack lakes
Brooktrout Lake
"Treat the earth well: it was not given to you by your parents, it was loaned to you by your children. We do not inherit the Earth from our Ancestors, we borrow it from our Children."
Effects of Acid Rain on Marble(marble is calcium carbonate)
George Washington:BEFORE acid rain
George Washington:AFTER acid rain
The pH of a lake is 8.0. Over a 10 year period, the pH of the water
becomes 1000x more acidic.1. Name an ion that has increased in the water over the
10 years?
2. What is the pH now?
3. If you were to use bromothymol blue to test the pH, what color would it be? [Use R.T.]
1. H2O + H2O H3O+ + OH-
2. H2SO4 + OH- HSO4- +
H2O3. HSO4- + H2O SO4
-2 + H3O+
4. OH- + H3O+ H2O + H2O5. NH3 + H2O NH4
+ + OH-
ACID BASE EQUATION
1 H2SO4 HSO4-
2 H3PO4
3 F-
4 NO3-
5 H2PO4-
6 H2O
7 SO4-2
8 HPO4-2
9 NH4+
10 H2O
H2PO4-
HF
HNO3
HPO4-2
OH-
HSO4-
PO4-3
NH3
H3O+
H3PO4 ↔ H+ + H2PO4-
HF ↔ H+ + F-
HNO3 ↔ H+ + NO3-
H2PO4- ↔ H+ + HPO4
-2
H2O ↔ H+ + OH-
HSO4-↔ H+ + SO4
-2
HPO4-2 ↔ H+ + PO4
-3
NH4+4 ↔ H+ + NH3
H3O+ ↔ H+ + H2O
PART C26. A, C, D27. D28. Presence of H+ ions29. C30. C31. (10.01mL)(0.100M)= MB(5.01ml)
0.200 M32. 733. Colorless to pink.34. 0.21 M35. 0.97 M
36. Reduces error, increases reliability37. Ca(OH)2 + H2SO4 CaSO4 + 2H2O
38. pH= 6.039. 0.33 M40. HCl – 9.50 ml NaOH – 3.80 ml41. 0.25 mL42. Methyl orange, brom blue, thymol blue
43. Between 4.4 and 5.544. Yellow
PART A1. 12. 33. 24. 45. 26. 37. 18. 29. 110. 411. 2
PART B
12. 413. 314. 415. 316. 117. 118. 119. 420. 221. 122. 323. 124. 225. 4
In a lab there were three flasks, one filled with methanol, another had NaOH, and the third HCl. ID these liquids.
TestTest Results
Bottle A Bottle B Bottle C
Methyl orange Yellow Yellow Yellow
Bromthymol Blue Blue Green Yellow
ConductivityConductor
Nonconductor
conductor
Reaction with Mg No Rxn No Rxn Rxn1. A student concluded that bottle C contained HCl.
Identify one way that supports this finding.
2. Explain in terms of pH, why methyl orange was the same for all three liquids.
What is the volume of 1.00 mole of any gas at STP?
Hint: Lab