u11ohnotes18f2005(5)

u11ohnotes18f2005(5) - Acid-Dissociation Constant, Ka For...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Acid-Dissociation Constant, K a For the generic reaction in sol’n: A + B ÅÆ C + D ] B [ ] A [ ] D [ ] C [ K ] REACTANTS [ ] PRODUCTS [ K a a o For strong acids, e.g., HCl… HCl H 1+ + Cl 1– BIG." " ] HCl [ ] Cl [ ] H [ K - 1 1 a . For weak acids, e.g., HF… HF H 1+ + F 1– 4 - - 1 1 a 10 x 6.8 SMALL" " ] HF [ ] F [ ] H [ K . Other K a ’s for weak acids: CH 3 COOH CH 3 COO 1– + H 1+ K a = 1.8 x 10 –5 HC 3 H 5 O 3 H 1+ + C 3 H 5 O 3 1– K a = 1.4 x 10 –4 HNO 2 H 1+ + NO 2 1– K a = 4.5 x 10 –4 The weaker the acid, the smaller the K a . stronger , larger “ . Assume 100% dissociation; K a not applicable for strong acids.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Find the pH of 1.75 M acetic acid (K a = 1.8 x 10 –5 ). CH 3 COOH CH 3 COO 1– + H 1+ 1.75 ] H [ ] COO CH [ ] COOH CH [ ] H [ ] COO CH [ 10 x 1.8 K 1 - 1 3 3 1 - 1 3 5 - a . . [ CH 3 COO 1– ] = [ H 1+ ] = x ] H [ M 0.00561 x 1.75 x 10 x 1.8 1 2 5 - . o pH = –log (0.00561) = 2.25 Hypobromous acid has K a = 2.5 x 10 –9 . Find pH if 145 g of acid are in 350 L of sol’n. HBrO H 1+ + BrO 1– M 10 x 4.28 L 350 g 96.9 g 145 ] HBrO [ 3 - 10 x 4.28 x
Background image of page 2
Background image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/23/2012 for the course CHEM 11 taught by Professor Staff during the Fall '08 term at Concordia AB.

Page1 / 3

u11ohnotes18f2005(5) - Acid-Dissociation Constant, Ka For...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online