# Nov_23 - Suggested Problems,23 27 33 39 65 77 Common Ion...

This preview shows pages 1–6. Sign up to view the full content.

Suggested Problems: Chapter 11 21,23, 27, 33, 39, 65, 77

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

View Full Document
Common Ion Effect Addition of salts of weak acids suppresses ionization of weak acids e.g. Calculate [H 3 O + ] after adding 0.010 mole of NaOAc to 1.00 L of 0.15 M HOAc (K a = 1.8 x 10 -5 ) HOAc(aq) + H 2 O(aq) H 3 O + (aq)+ OAc - (aq) 0.15 0 0.010 -x +x +x [H 3 O + ] = 2.7 x 10 -4 M (originally 1.64 x 10 -3 M)
Bases Strong bases dissociate completely (NaOH, KOH) [OH-] = original [B] Weak bases dissociate only slightly (NH 3 , CH 3 NH 2 ) The extent is reflected in the size of K b K b = [ BH + ][ OH - ] [ B ] Bases (B) produce OH - ions in water B + H 2 O BH + + OH -

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

View Full Document
Calculate the pH of 0.35 M trimethyl amine, (CH 3 ) 3 N (K b = 6.3 x 10 -5 ) (CH 3 ) 3 N + H 2 O (CH 3 ) 3 NH + + OH - 0.35 0 0 0.35 – x x x K b = [ BH + ][ OH - ] [ B ] = x 2 .35 x = 6.3 x 10 5 x = [ OH - ] = 4.7 x 10 -3 M K w = [H 3 O + ][OH - ] = 10 -14 so [H 3 O + ] = 2.1x 10 -12 and pH = 11.68
Hydrolysis Salts of weak acids or bases react with water to

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 14

Nov_23 - Suggested Problems,23 27 33 39 65 77 Common Ion...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online