Honors Chem Unit 10 Acids & Bases Ch 14 & 15 Properties of Acids: Properties of Acids: –Sour Taste –Electrolytes –Change indicator colors –React with metals to form hydrogen –React with carbonates to form carbon dioxide –React with bases to form salt & water –Produces H + in water –To name: Look at ending: »-ate polyatomic ions  -ic acids »-ite polyatomic ions  -ous acids »-ide monatomic ions  hydro –ic acid

Properties of bases: Properties of bases: –Bitter –Feel Slippery –Electrolytes –Change indicator colors –React with acids to produce salt & water –Produce OH - in water –To name: name the metal and hydroxide

Self ionization of water: Self ionization of water: H 2 O + H 2 O  H 3 O + + OH - H 2 O + H 2 O  H 3 O + + OH - –Hydronium ion H 3 O + –Hydroxide ion OH - Only 1X 10 –14 M of water molecules do this so [H 3 O + ][OH - ] = 1X 10 –14 M Only 1X 10 –14 M of water molecules do this so [H 3 O + ][OH - ] = 1X 10 –14 M –If [H 3 O + ]=[OH - ] neutral solution –If [H 3 O + ]>[OH - ] acidic solution –If [H 3 O + ]<[OH - ] basic or alkaline solution If the hydroxide concentration is 1 X 10 –4 M, what is the hydronium ion concentration? If the hydroxide concentration is 1 X 10 –4 M, what is the hydronium ion concentration?

pH pH »Acid neutral base pOH pOH pH +pOH=14 –Use to find one given the other. –Find the pOH if the pH is 8.2. [H + ]= 10 -pH [H + ]= 10 -pH –Use to find [H 3 O + ] given the pH –Find the [H + ] given a pH of [OH - ]= 10 -pOH [OH - ]= 10 -pOH –Use to find [OH - ] given the pOH –Find the [OH - ] given a pOH of 7.5.

Formulas: Formulas: [H 3 O + ][OH - ] = 1 X 10 –14 M [H 3 O + ][OH - ] = 1 X 10 –14 M Use to find one [] given the other [] Use to find one [] given the other [] –Find the hydroxide ion concentration if the hydronium ion concentration is 1 X M. Is this acidic basic or neutral? pH=-log [H 3 O + ] pH=-log [H 3 O + ] –Use to find pH given [H + ] –Find the pH if the hydronium ion concentration is 2.1 X M. pOH= -log [OH - ] pOH= -log [OH - ] –Use to find pOH given [OH - ] –Find the pOH if the hydroxide ion concentration is 4.1 X M.

To measure pH: To measure pH: –Use acid/base indicators: change color based on [hydrogen ion ], many types pg 604 –pH paper- have indicators on them –pH meter

Indicator Lab Purpose: use indicators to determine acids and bases Purpose: use indicators to determine acids and bases Materials: pH paper, red and blue litmus paper, universal indicator, soap solution, HCl, NaOH, vinegar, ammonia, page protector Materials: pH paper, red and blue litmus paper, universal indicator, soap solution, HCl, NaOH, vinegar, ammonia, page protector Procedure: Procedure: –Create a chart of items to be tested and put it in page protector –Create a chart for data –Put 5 drops of each item to be tested on page protector in appropriate box –Tear red litmus into 5 pieces. Test each and record. –Repeat for blue and pH paper –Put 1 drop of universal indicator in each sample and record.

Indicator Lab Questions 1. Which of the items were acids? How do you know? 1. Which of the items were acids? How do you know? 2. Which of the items were bases? How do you know? 2. Which of the items were bases? How do you know? 3. Pick 3 different pH values and solve for the pOH, [H + ] & [OH - ]. Show formulas and all work for credit. 3. Pick 3 different pH values and solve for the pOH, [H + ] & [OH - ]. Show formulas and all work for credit.

Arrhenius acid: Produce H + ion Arrhenius acid: Produce H + ion Arrhenius base: Produce OH - ion Arrhenius base: Produce OH - ion Bronsted-Lowery Acid: H + donor Bronsted-Lowery Acid: H + donor Bronsted Lowery Base: H + acceptor Bronsted Lowery Base: H + acceptor **More Broad definition than Arrhenius** **More Broad definition than Arrhenius** Lewis acid- can accept pr of e- to form a covalent bond (H + ) Lewis acid- can accept pr of e- to form a covalent bond (H + ) Lewis base- can donate pr of e- to form a covalent bond (OH - ) Lewis base- can donate pr of e- to form a covalent bond (OH - ) –Look for lone pr –** is more broad than other two def.**

Be able to identify conjugate acid base pr: Be able to identify conjugate acid base pr: –Acid becomes conjugate base –Base becomes conjugate acid Amphoteric- can be acid or base Amphoteric- can be acid or base Identify the conjugate acid-base pairs in the following reactions. Identify the conjugate acid-base pairs in the following reactions. H 2 SO 4 + H 2 O  HSO H 3 O + H 2 SO 4 + H 2 O  HSO H 3 O + HI(aq) + H 2 O(l)  H 3 O + (aq) + I - (aq) HI(aq) + H 2 O(l)  H 3 O + (aq) + I - (aq)

Strong acid- completely ionizes becomes weak CB Strong acid- completely ionizes becomes weak CB Weak acid- incompletely ionizes becomes strong CB Weak acid- incompletely ionizes becomes strong CB Can write ionization equation: Can write ionization equation: Can write acid dissociation constant (K a ) Can write acid dissociation constant (K a ) K a = [Products]/[Reactants] K a = [Products]/[Reactants] –Don’t include water –Smaller #=weaker acid –Polyprotic acids- take 1 H at a time Also applies to bases called K b Also applies to bases called K b

Write the steps in the complete ionization of H 2 S. Write the steps in the complete ionization of H 2 S. Write the ionization equation and acid ionization constant expression for the following acids. Write the ionization equation and acid ionization constant expression for the following acids. –a. HCl –b. HNO 2 –c. H 3 PO 4 Write ionization equations and base ionization constant expressions for the following bases. Write ionization equations and base ionization constant expressions for the following bases. –a. propylamine (C 3 H 7 NH 2 )

How to find info about weak acids Acids 1. List major species 2. Write balanced equations for the H+ production 3. Using the values of K decide which will produce 4. Write the Keq for the dominant eq 5. Do ICE chart 6. Sub into the Keq 7. Solve for the easy way 8. Verify using 5% rule 9. Calculate [H+] and pH.

If given numbers fill in: If given numbers fill in: A.100M solution of ethanoic acid is partially ionized. The [H + ] is 1.34 X M. What is the K a of ethanoic acid? A.100M solution of ethanoic acid is partially ionized. The [H + ] is 1.34 X M. What is the K a of ethanoic acid?

If acetic acid has a k a = 1.8 X 10 -5, find the pH, pOH, [H + ], [OH - ] of a 1.00M solution. If acetic acid has a k a = 1.8 X 10 -5, find the pH, pOH, [H + ], [OH - ] of a 1.00M solution.

Neutralization- Double displacement Neutralization- Double displacement –Acid + Base  salt + water n 1 M 1 V 1 =n 2 M 2 V 2 –5.0 mL 0.5 M Nitric acid will neutralize how much 2.0 M calcium hydroxide? –10.0 mL of 1.5 M Sulfuric acid will neutralize how much 3.0 M aluminum hydroxide? –Can find acid & base that form salt »NaCl »NaHCO 3

Salts Salts –Made from an acid & base Strong acid + strong base  neutral salt soln. Strong acid + strong base  neutral salt soln. Weak acid + strong base  basic salt soln. Weak acid + strong base  basic salt soln. Strong acid + weak base  Acidic salt soln. Strong acid + weak base  Acidic salt soln. Be able to predict the acid & base that make the salt Be able to predict the acid & base that make the salt Buffers- solution where the pH remains constant when an acid/base are added Buffers- solution where the pH remains constant when an acid/base are added Can absorb or release H + Can absorb or release H +

–Titration- Use known to find unknown –Need mol ratio for H + :OH- –Steps in titration: »Measure volume of acid soln. Of [unknown] in flask »Add indicator »Measured volume of base [known] ‘standard’ are added until slight color change (endpoint) »Use nMV=nMV –A 25 mL soln of hydrochloric acid neutralized by 18mL of 1.0M NaOH. What is the [hydrochloric acid]?