{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ch15 - 15 15.1 Aqueous Equilibria Acids and Bases(a...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
15 Aqueous Equilibria: Acids and Bases 15.1 (a) H 2 SO 4 (aq) + H 2 O(l) 5 H 3 O + (aq) + HSO 4 S (aq) conjugate base (b) HSO 4 S (aq) + H 2 O(l) 5 H 3 O + (aq) + SO 4 2 S (aq) conjugate base (c) H 3 O + (aq) + H 2 O(l) 5 H 3 O + (aq) + H 2 O(l) conjugate base (d) NH 4 + (aq) + H 2 O(l) 5 H 3 O + (aq) + NH 3 (aq) conjugate base 15.2 (a) HCO 3 S (aq) + H 2 O(l) 5 H 2 CO 3 (aq) + OH S (aq) conjugate acid (b) CO 3 2 S (aq) + H 2 O(l) 5 HCO 3 S (aq) + OH S (aq) conjugate acid (c) OH S (aq) + H 2 O(l) 5 H 2 O(l)(aq) + OH S (aq) conjugate acid (d) H 2 PO 4 S (aq) + H 2 O(l) 5 H 3 PO 4 (aq) + OH S (aq) conjugate acid 15.3 HCl(aq) + NH 3 (aq) 5 NH 4 + (aq) + Cl S (aq) acid base acid base conjugate acid-base pairs 15.4 (a) HF(aq) + NO 3 S (aq) 5 HNO 3 (aq) + F S (aq) HNO 3 is a stronger acid than HF, and F S is a stronger base than NO 3 S (see Table 15.1). Because proton transfer occurs from the stronger acid to the stronger base, the reaction proceeds from right to left. (b) NH 4 + (aq) + CO 3 2 S (aq) 5 HCO 3 S (aq) + NH 3 (aq) NH 4 + is a stronger acid than HCO 3 S , and CO 3 2 S is a stronger base than NH 3 (see Table 15.1). Because proton transfer occurs from the stronger acid to the stronger base, the reaction proceeds from left to right. 15.5 (a) Both HX and HY have the same initial concentration. HY is more dissociated than HX. Therefore, HY is the stronger acid. (b) The conjugate base (X S ) of the weaker acid (HX) is the stronger base. (c) HX + Y S 5 HY + X S ; Proton transfer occurs from the stronger acid to the stronger base. The reaction proceeds to the left. 15.6 [H 3 O + ] = _14 w _ _6 1.0 x 10 K = [ ] 5.0 x OH 10 = 2.0 x 10 S 9 M Because [OH S ] > [H 3 O + ], the solution is basic. 131
Background image of page 1

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

View Full Document Right Arrow Icon
15.7 K w = [H 3 O + ][OH S ]; In a neutral solution, [H 3 O + ] = [OH S ] At 50 o C, [H 3 O + ] = [OH S ] = _14 w = 5.5 x 10 K = 2.3 x 10 S 7 M 15.8 (a) [H 3 O + ] = _14 w _ _6 1.0 x 10 K = [ ] 1.58 x OH 10 = 6.3 x 10 S 9 M pH = S log[H 3 O + ] = S log(6.3 x 10 S 9 ) = 8.20 (b) pH = S log[H 3 O + ] = S log(6.0 x 10 S 5 ) = 4.22 15.9 (a) [H 3 O + ] = 10 S pH = 10 S 7.40 = 4.0 x 10 S 8 M [OH S ] = _14 w + _8 3 1.0 x 10 K = [ ] 4.0 x O 10 H = 2.5 x 10 S 7 M (b) [H 3 O + ] = 10 S pH = 10 S 2.8 = 2 x 10 S 3 M [OH S ] = _14 w + _3 3 1.0 x 10 K = [ ] 2 x O 10 H = 5 x 10 S 12 M 15.10 (a) Because HClO 4 is a strong acid, [H 3 O + ] = 0.050 M. pH = S log[H 3 O + ] = S log(0.050) = 1.30 (b) Because HCl is a strong acid, [H 3 O + ] = 6.0 M. pH = S log[H 3 O + ] = S log(6.0) = S 0.78 (c) Because KOH is a strong base, [OH S ] = 4.0 M. [H 3 O + ] = _14 w _ 1.0 x 10 K = [ ] 4.0 OH = 2.5 x 10 S 15 M pH = S log[H 3 O + ] = S log(2.5 x 10 S 15 ) = 14.60 (d) Because Ba(OH) 2 is a strong base, [OH S ] = 2(0.010 M) = 0.020 M. [H 3 O + ] = _14 w _ 1.0 x 10 K = [ ] 0.020 OH = 5.0 x 10 S 13 M pH = S log[H 3 O + ] = S log(5.0 x 10 S 13 ) = 12.30 15.11 BaO(s) + H 2 O(l) 5 Ba(OH) 2 (aq); BaO, 153.33 amu 0.25 g BaO x _ 2 2 1 mol Ba(OH) 1 mol BaO 2 mol OH x x 153.33 g BaO 1 mol BaO 1 mol Ba(OH) = 3.26 x 10 S 3 mol OH S [OH S ] = _3 _ 3.26 x mol 10 OH 0.500 L = 6.52 x 10 S 3 M [H 3 O + ] = _14 w _ _3 1.0 x 10 K = [ ] 6.52 x OH 10 = 1.53 x 10 S 12 M pH = S log[H 3 O + ] = S log(1.53 x 10 S 12 ) = 11.81 15.12 HOCl(aq) + H 2 O(l) 5 H 3 O + (aq) + OCl S (aq) initial (M) 0.10 ~0 0 change (M) S x +x +x equil (M) 0.10 S x x x x = [H 3 O + ] = 10 S pH = 10 S 4.23 = 5.9 x 10 S 5 M [OCl S ] = x = 5.9 x 10 S 5 M; [HOCl] = 0.10 S x = (0.10 S 5.9 x 10 S 5 ) M K a = + _ _5 _5 3 _5 [ ][ ] (5.9 x )(5.9 x ) O OCl 10 10 H = [HOCl] (0.10 _ 5.9 x ) 10 = 3.5 x 10 S 8 132
Background image of page 2
This value of K a agrees with the value in Table 15.2.
Background image of page 3

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

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}