Nov 279:06 PM Due: RG 19
WU: Name or write formula • H2S
• H2SO4
• HCl
• HClO4
• HClO3
• HClO2
• HClO
• H3PO4
• H2C2O4
• H2CO3
• HBr
• HI
• magnesium hydroxide
• aluminum hydroxide
• sodium hydroxide
Dec 44:04 PM Review: How to name acids
~ Binary Acids: HX (criss cross charges) Hydro ____ ic acid = Hnonmetal acid must drop 'ide' ending and add 'ic' Ex: HBr, HCl, H2S
~Ternary Acids: HX (criss cross charges) _______ ic acid = Polyatomicate acid Ex: HNO3, H2SO4
________ous acid = Polyatomicite acid Ex: HNO2, H2SO3
H
+OH
H
3O
+Nov 278:19 PM
Chapter 19:
Characteriscs Definions pH calculaons
Apr 253:29 PM
PropertyAcids (HX) H+ and X-(anion)
Bases (YOH)
Y+=Metal; OH- hydroxide
Taste Sour Bitter
Feel Like liquid water , BURNS Like soap (slippery)
Reactivity
with MetalsM + HX --> MX + H2(gas)
YOH + M <--> NR ( NO REACTION because reversible, so essentially nothing happens...)
Conductivity (aqueous soln)
HX + H2O --> H3O+ + X- Ions are electrolytes Strong acids have very polar covalent bonds so will actually ionize in water.
YOH --> Y+ + OH- Ions are electrolytes…
bases are ionic and dissociate.
Nov 278:19 PM
Acid /Base Strength
• Strength is not a measure of concentration (i.e. molarity) 18M HC2H3O2 = ________ & 0.01M HCl = ____________
• Strong Acids ionize completely = 100% ionization
HA + H2O --> H3O+ + A-
• 6 Strong Acids (binary and polyatomic ions)
~Hydrochloric acid
~Hydroiodic acid
~Hydrobromic acid
~Nitric acid
~Perchloric acid
~Sulfuric acid
Nov 278:19 PM Strong Bases dissociate completely (100%)
• YOH --> Y+ + OH- (100% forward rxn)
• Strong bases are hydroxides of group 1A and 2A Elements most likely to give up ___ to OH
• Weak acids and bases =
INCOMPLETE IONIZATION OR DISSOCIATION
Reach equilibrium: (reverse rxn likely)
HA + H
2O <---> H
3O
++ A
-YOH + H
20 <---> Y
++ OH
-Ex:
Nov 278:19 PM Acid/Base Definions
Arrhenius: how the substance behaves in water
•Acids form hydronium in water HX + H20 --> H30+ + X-
•Bases form hydroxide in water (write aq to show in water) YOH --> Y+ + OH-
Bronsted: more inclusive definition b/c not just water
•Acids are proton (H+- hydrogen ion) donors
•Bases are proton acceptors
Lewis: how the substance relates to lone pair of e of other substances
•Acid accept lone pairs of e in order to bond
•bases share their lone pairs of e in a bond
Apr 268:08 AM
Nov 278:30 PM water is amphoteric
Nov 278:19 PM
Conjugates
**Conjugates are products, not reactants**
Conjugate Acids:
•Form from bases
•Are the species formed once the base accepts the hydrogen Ex. NH3 is a base and accepts a H+ ....once the NH3 has accepted a hydrogen it makes NH4+ which is the conjugate acid of NH3
Conjugate Bases:
•From from acids
•Are the species formed once the acid donates a proton Ex. HCl is an acid, it donates a H+....once the H+ is gone it makes Cl‐ which is the conjugate base of HCl
Nov 278:19 PM
What is the conjugate base for each of the following acids?
H2SO4 NH4+ H2O
Nov 278:19 PM
Idenfy the acid, base, conjugate acid and conjugate base HC2H3O2 + H2O → H3O+ + C2H3O2‐
HCl + SO32‐ → HSO3‐ + Cl‐
NH3 + HNO2 → NO2‐ + NH4+
NH4+ + CO32‐ → NH3 + HCO3‐
HClO + SO42‐ → HSO4‐ + ClO‐
HSO4‐ + OH‐ → H2O + SO42‐
Write the formula for NH3 acng as an Arrhenius Base:
Apr 255:12 PM Nov 278:19 PM
Made for a Danish Beer Company in 1909 by Soren Sorensen revised in 1924
~ pH measures acidity (H+ concentration)
~ Auto-ionization of water (pH of 7)
H2O H3O+ + OH-
pH Scale
Nov 278:19 PM
Formulas for calculating pH: MEMORIZE!
pH= - log [H3O+] pOH= -log[OH-]
pH + pOH = 14 [OH-] [H3O+] = 1.00 x 10-14 [H3O+] = antilog(-pH) [OH-] = antilog(-pOH)
• For strong acids, the [ H3O+ ] is equal to the molar concentration of the acid.
• For strong bases, the[OH-] is equal to the molar concentration of the base times the subscript on the hydroxide ion.
ex: 4M Ba(OH)2 -->4M(2 subscript) = 8M
***** anlog = 10^
Nov 278:19 PM Examples:
For each of the following calculate pH, pOH, [H3O+], [OH-]
1. The hydroxide ion concentration of an aqueous solution is 6.4x 10-5M.
Dec 41:57 PM
2. 0.75M solution of nitric acid.
Nov 278:19 PM
3. Hydronium/hydrogen ion concentration of 0.00118M.
4. What is the pH of a 2.4M sodium hydroxide solution?
Nov 278:19 PM
5. What is the pH of a 0.005M magnesium hydroxide solution?
6. pH of 9.6. Before you solve, predict if the concentration will be greater than, less than or equal to 1.0 x 10-7 M.
calcium
Dec 44:43 PM
HW: Calc the H3O+ and OH for each. Assume each is a SA or SB
a) 0.05M Sodium Hydroxide b) 0.0025M Sulfuric acid c) 0.013M Lithium hydroxide d) 0.150M Nitric Acid e) 0.0200M Calcium hydroxide f) 0.390M Hydrobromic acid
What is the pH of each of the above solns?
A soln of NH3 has a pH of 11.00. What are the concentrations of hydronium and hydroxide ions?
Dec 410:41 PM Answers to HW Problems:
1. a. 0.05, 2 x 10-13 b. 4.0 x 10-12 , 0.0025 c. 0.013, 7.7 x 10-13 d. 6.67 x 10-14, 0.150 e. 0.0400, 2.50 x 10-13 f. 2.56 x 10-14 , 0.390
2. a. 12.70 b. 2.60 c. 12.11 d. 0.824 e. 12.602 f. 0.409
3. 1.0 x 10-11 , 1.0 x 10-3
Apr 255:15 PM
hp://www.bgfl.org/bgfl/custom/resources_p/client_p/ks3/science/acids/index.htm
Cute indicator website!!!
Quiz – Acid Base Definitions 1. List two physical properties of acids.
2. Which will conduct electricity better? Why? 3M HC2H3O2
OR 0.001M HCl 3. What is a Bronsted base?
4. Write the equation for HCO3- acting as an Arrhenius acid.
Write the conjugate for each of the following.
Acid Conjugate Base Base Conjugate Acid
HSO4 OH
HNO3 H2PO4
HF Cl
May 164:20 PM Warm Up:
What happens if the soil of a hydrangea plant is too acidic?
Why do we call a hydrogen ion a 'proton'?
What do acids produce in water?
Voice Activated!
Study for Quiz (Calculations and Definitions) at end of class?
Nov 278:19 PM
Indicators
Indicators: are substances that are one color in an acid and a different color in a base
• Litmus Blue to red – acid Red to blue - base
• Phenolphthalein Pink in base
Clear in acid or neutral
Apr 255:24 PM Apr 255:24 PM
Apr 268:09 AM
pH of Weak Acids and bases:
Weak acids and bases only partially ionize in water. So we use a value of ka or kb to solve for [H3O+] or [OH-]
Apr 306:17 AM
Nov 279:03 PM
Acid Base Indicator Cabbage Juice Lab:
~Please use caution because will stain clothes
~DO NOT MIX UP solutions- the standard solutions on left, sample solutions on right
~ Wash all equipment very well when done!
HW: PS 19 A and Indicator exploration!
Apr 255:26 PM
WU: Which of the following conduct electricity better?
a. 6M HCl or 6M C2H3O2 b. Ca(OH)2 Or Al(OH)3
c. 0.0001M NaCl or 0.00001MHCl
What does 100% ionization mean? List an acid and a base that will ionize 100%
Nov 278:19 PM
Acid Base Reacons
Neutralization: when acids react with bases
Acid + Base → Salt + water HX + YOH → YX + HOH
Nov 278:19 PM Ex.
Hydrochloric acid reacts with sodium hydroxide
Hydrochloric acid reacts with sodium bicarbonate
Nitric acid reacts with magnesium hydroxide
Calcium hydroxide reacts with acetic acid
Nov 278:19 PM
Hydrolysis- Opposite of Neutraliztation - a salt reacts with water
Salt + water → Acid + Base YX + HOH → HX + YOH
Nov 278:19 PM
Ex. Write the equation for the hydrolysis of the following salts
Sodium chloride
Calcium phosphate
Lithium nitrate
Aluminum bromide
May 110:37 AM You Try!
Hydrolysis of ammonium nitrate
neutralization of barium hydroxide and nitric acid
hydrolysis of potassium dichromate
neutralization of oxalic acid and ammonium hydroxide
Nov 279:18 PM Hydrolysis Lab:
Equipment glass stirring rod, indicator paper, test tubes
Chemcials: Share salts and do not mix!
BE SURE YOU ONLY USE A LITTLE SCOOP OF SALT 1 cm on scoopula works!
Parent acid and parent base = these indicate where the salt came from.
HW PS 19 B
Apr 255:29 PM
Write the equations for the following neutralization reactions:
Hydrochloric acid reacts with sodium bicarbonate:
Nitric acid reacts with magnesium hydroxide
Sulfuric acid reacts with sodium hydroxide
Calcium hydroxide reacts with acetic acid
Dec 411:08 PM
Apr 268:09 AM
