Ch. 17 Acid-Bases!!! Flashcards
What are the 3 definitions for Acids and bases?
Lewis, Bronsted-Lowry, and Arrhenius definitions. These will be on the study guide sheets!!!
What is the Bronsted-Lowry definition of Acids and bases?
Acids are proton donors (give an H+), and bases are proton acceptors (removes an H+ from eqn).
What are amphoteric substances? Example?
These are substances that can act as both an acid and base. WATER!!
Monoprotic VS. Polyprotic acids?
MONOprotic acids are capable of donating only 1 proton, while POLYprotic are capable of donating 2 or more protons.
What are conjugate acid-base pairs? Why are these important?
a pair of substances that differ from eachother by only the 1 H+ proton. EVERY rxn between a Bronsted acid and base has 2 conjugate A-B pairs!
What makes acids STRONG acids?
strong acids completely ionize to H+. So HCl is essentially just the H+. They are great conductors of electricity.
What are WEAK acids? What type of eqn are weak bases in?
Acids that don’t completely ionize. Weak acids are in equilibrium equations!
What are values for Ka and Kb always going to be under? For WEAK ACIDS & BASES
Ka and Kb values will ALWAYS be <1 for weak acids and bases.
What is the difference of Anions that are conjugate bases for Strong acids/Weak acids?
Anions that are conj. bases for STRONG acids are so weak, cannot dissociate in H2O, have no effect on pH.
Anions that are conj. bases for WEAK acids are themselves a Weak base! Can raise pH of sol’n
What are 2 categories for Acidic Cations?
- Metal cations with 2+ or 3+ charges (Fe3+, Cu2+, etc.)
2. Ammonium ions! (NH4 +)
What are Basic Cations?
basic cations are conj. bases for acidic cations.
What are the 4 types of Acid-Base reactions? What are the pH for each type? (on Week 5, Pg. 7 the details!!!)
Weak acid - Strong base: basic, pH>7
Strong acid - Strong base: pH=7
Strong acid - Weak base: pH<7
Weak acid - Weak base: pH depends of Ka and Kb of conj. base/conj. acid!
How do polyprotic acids ionize? How do the steps differ?
polyprotic acids have 2 or more ionizable protons. you can use equil. eqn for each successive step (usually). the Ka/Kb of each step is FAR smaller than the last!
What are Lewis Acids/ Lewis Bases?
Lewis acids are the e- pair acceptor, while the Lewis bases are the e- pair donors. Using Lewis Diagrams!
Why are metal cations often Lewis Acids?
Metal cations are often Lewis acids due to the open d-orbitals they have. Fe3+,Cu2+,Pb2+,etc.
What are Oxyacids?
Acids that contain oxygen. the more oxygens, the stronger the acid!
How does bond strength tie in to acidity?
As the strength of the acid increases, the bond strength decreases!
