Acids and Bases Properties, Reactions, and Calculating pH
Acids and Bases Properties, Reactions, and Calculating pH Standards **STANDARD SET 5: Acids and Bases 5. Acids, bases, and salts are three classes of compounds that form ions in water solutions. As a basis for understanding this concept: a. Students know the observable properties of acids, bases, and salt solutions. 5. b. Students know acids are hydrogen-ion-donating and bases are hydrogen-ionaccepting substances.
5. c. Students know strong acids and bases fully dissociate and weak acids and bases partially dissociate. 5. d. Students know how to use the pH scale to characterize acid and base solutions. 5. e.* Students know the Arrhenius, Brnsted-Lowry, and Lewis acidbase definitions. 5. f.* Students know how to calculate pH from the hydrogen-ion concentration. 5. g.* Students know buffers stabilize pH in acidbase reactions. Properties Acids Electrolytes React with metals to
produce H2 gas Form H3O+ ions in water Tastes sour Bases slippery Form OH ions in water Tastes bitter Examples: soap, cocoa Examples: vinegar, lemon powder, ammonia,
14 Strong bases pH < 7 = acidic pH = 7 = neutral pH > 7 = basic Various Definitions of Acids/Bases Arrhenius Acid a substance which forms
hydronium (H3O+) ions in water. Arrhenius Base a substance which forms hydroxide (OH) ions in water. Brnsted-Lowry Acid a substance which can donate a proton (an H+). Brnsted-Lowry Base a substance which can accept a proton (an H+). Lewis Acid a substance which can accept a lone pair of electrons. Lewis Base a substance which can donate a lone pair of electrons.
H+ base Conjugate Acid/Base Pairs NH3 (aq) + H2O(l) + H base NH4+(aq)+ OH(aq) +
H conjugate acid Water is an Acid/Base H2O (l) + H2O (l) H3O+ (aq) + OH(aq) hydronium ion
hydroxide ion But water is a weak acid and a weak base, so only a small amount of water will form these ions, the rest will remain as H2O. Measuring the Strength of Acids/Bases We often speak of acid concentrations in molarity (ex. 2.0 M HCl solution, aka
) 2.0 mol HCl 1 L solution But which is stronger 2.0 M HCl solution or 2.0 M CH3COOH solution? Its more important to know the concentration of hydronium ions. [H+] really means [H3O+]
Calculating pH pH = log10[H3O+] Example: If [H3O+] = 1 x 105 M, what is the pH? pH = log10[1 x 105] pH = 5 Back-calculating concentration (1) x log10[H3O+] = pH x (1) log10[H3O+] = pH 10
pH < 7 = acidic pH = 7 = neutral pH > 7 = basic Neutralization H3O+ (aq) + OH(aq) H2O (l) + H2O (l) Large amounts of H3O+ and OH cannot exist at the same time in a solution. Whichever
ion has the larger amount will reduce the lesser amount. What you would see: HCl (aq) + NaOH (aq) NaCl (aq)+ H2O (l) Titration H3O+ (aq) + OH(aq) H2O (l) + H2O (l) Titration is the experimental process of
figuring out the pH of a mystery solution by neutralizing it by incrementally adding small amounts of a known solution. The titration is complete when we reach the equivalence point (where [H3O+]=[OH] ). n=CxV moles = concentration x volume Titration H3O+ (aq) + OH(aq) H2O (l) + H2O (l)
Example: How many moles of H3O+ would it take to neutralize 5 liters of a 0.1 M NaOH solution? n=CxV mol n = (0.1 L )(5 L) n = 0.5 mol H3O+ Buffers
Buffers stabilize the pH of acids. The salt of the conjugate base to the acidic solution can act as a buffer. CH3COOH(aq)+H2O(l) acid CH3COO(aq)+ H3O+(aq) conjugate base How would the equilibrium shift if we added
NaCH3COO to the acidic solution? adding more CH3COO H He Li Be B C
N O F Na Mg Al Si
P S Cl Ar K Ca Ne
Br Kr I Xe H He Li Be B
C N O F Na Mg Al
Si P S Cl Ar K Ca
Ne Br Kr I Xe 4 e in valence shell Measuring the Strength of Acids/Bases
We often speak of acid concentrations in molarity (ex. 2.0 M HCl solution, aka ) 2.0 mol HCl 1 L solution But which is stronger 2.0 M HCl solution or 2.0 M CH3COOH solution? Since we use both strong and weak acids, a
more consistent measurement would tell us just the concentration of hydronium ions. [H+] really means [H3O+] H3O+ (aq) + OH(aq) H2O (l) + H2O (l) H3O+ (aq) + OH(aq) H2O (l) + H2O (l)
As Neil Patterson has said "Painting is all about passion. If you respond to the passion you have inside yourself, that's when the real painting comes out". (Neil Patterson Fine Art; About the Artist) This is clearly visible with three...
Landforms and Climate. The Canada/ United States border-World's longest undefended border (meaning they are friendly) How big is Canada compared to other countries in physical size?- World's 2nd largest country. Explain these vocabulary words and why they are important to...
The Philistines had two main temples in honor of Dagon-one at Ashdod and one at Gaza, with smaller temples elsewhere. More Facts, Please! Lowing cows-In Bible times the terms used in regard to cattle were the same as now: a...
Section 2.2—Naming Chemicals. We need to be able to name the chemicals in the antacids! Binary Ionic compounds. The first type of compound is the binary ionic compound. Definitions. Binary Ionic Compound - compound containing two elements—one metal and one...
The State Park and Cherokee National Forest offer hiking trails, camping and several public launch areas so the town of Reliance gets very busy during rafting season and Flip Flop Burger is the only place to go.
It is the only section of the SIS® that is standardized. Section 1 - Support Needs Scale. Section 1, the Support Needs Scale is comprised of 6 sections, or domains, Parts A - F that encompass all life areas. The...
Investigator Disclosure of SFIs. SFIs include financial interests that are related to an Investigator's institutional responsibilities. Consider verifying Investigator disclosures. Institutions are responsible for determining whether an SFI relates to NIH-funded research and if it is an FCOI
The herbs Niprisan: (1) S. bicolor (2) P. osun (3) Clove (4) P. guineense The bases for the actions of Sorghum bicolor and Pterocarpus osun are unknown, but they are rich in brightly coloured red/orange flavonoids. They probably act as...
Ready to download the document? Go ahead and hit continue!