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Marissa Levy Boyi Zhang Shana Zucker. Unit 3 Acids and Bases. Brönsted - Lowry. Arrhenius Acid- An acid is a substance that when dissolved increases H + concentration Base- A base is a substance that when dissolved increases OH - concentration. Lewis. Arrhenius.
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Marissa Levy Boyi Zhang Shana Zucker Unit 3 Acids and Bases
Brönsted - Lowry Arrhenius Acid- An acid is a substance that when dissolved increases H+ concentration Base- A base is a substance that when dissolved increases OH- concentration Lewis Arrhenius What is an acid? What is A Base? Lewis Acid- An acid is a substance that is an electron-pair acceptor Base- A base is a substance that is an electron-pair donor Bronsted-Lowry Acid- An acid is a substance that donates a proton Base- A base is a substance that accepts a proton
Conjugate Acids And Bases What’s an acid and what is a base? NH3 + H20 ⇆ NH4+ + OH- Base Acid Conjugate Acid Conjugate Base
Strong Disassociate Ionize completely Weak Disassociate Ionize Partially Have Ka or Kb values What is the difference Between Weak and Strong?
How do you calculate pH of a strong solution at equilibrium? Write the equilibrium equation Whatever concentration you start with is the concentration you end with Calculate the pH Strong Solutions at Equilibrium
How do you calculate pH of a strong solution at equilibrium? 0.25 M of HClO3 in water. Strong Solutions at Equilibrium KOH(aq) + H20 (l) ⇆ K+ (aq) + OH- (aq) pOH= -log(.25)= .602 pH= 14- pOH= 13.40
How do you calculate pH of a weak solution at equilibrium? Write the equilibrium equation Write the ICE equation Solve for X Calculate the pH Weak Solutions at Equilibrium
How do you calculate pH of a solution at equilibrium?’ A 0.25 M Phosphoric solution is prepared in water. • Ka = 7.5 x 10-3 • H3PO4 + H₂O (l) ⇆ H+ + H2PO4- Ka = 7.5 x 10-3 • 2. • 3. 7.5 x 10-3 = x2/ .25 • x= .0433 • 4. pH= -log(.0433)= 1.36 Weak Solutions at Equilibrium
N1C1V1= N2C2V2 If 15.0 mL of HCN is completely titrated with 25.0 mL of 0.100 M NaOH calculate the concentration of HCN. 1(C1) (15.0)= 1(.100)(25.0) C1= .167 M Titration Formula
Strong Acid Strong Base H+ + OH-⇆ H₂O (l) Writing Titration Equations
WeakAcid Strong Base • H3PO4 + OH-⇆ H₂O (l) + H2PO4- WeakAcid Weak Base • HF + N2H4⇆ HN2H4+ + F- Writing Titration Equations
Buffer A weak-acid base conjugate pair They resist changes in pH What is a Buffer?
pH= pKa + log (base)/(acid) pOH= pKb + log (acid)/(base) Calculating pH of a Buffer
Sources • http://chemistry.about.com/od/acidsbase1/ss/titrationcurves_2.htm • http://www.chemistry.wustl.edu/~edudev/LabTutorials/Buffer/Buffer.html • http://www.quickmeme.com/meme/36jbu2/