Acids Lesson 16 Amphiprotic Ions Acids or Bases?
Amphiprotic Ions H3PO4 Acid H2PO4- Amphiprotic HPO42- Amphiprotic PO43- Base Amphiprotic ions have a Ka and a Kb. If you compare them, you can tell how the ion will behave in water as either an acid or base. If the Ka > Kb, then the ion is an acid. If the Kb > Ka, then the ion is an base.
1. Is H2PO4- an acid or base when in water. Write the 1. Is H2PO4- an acid or base when in water? Write the hydrolysis equation for this ion. Ka (H2PO4-) = 6.2 x 10-8 Kb (H2PO4-) = = Kw Ka(H3PO4) = 1 x 10-14 7.5 x 10-3 = 1.3 x 10-12 Ka > Kb Acid H2PO4- + H2O ⇄ HPO42- + H3O+
2. Is HPO42- an acid or base when in water. Write. the 2. Is HPO42- an acid or base when in water? Write the hydrolysis equation for this ion. Ka (HPO42-) = 2.2 x 10-13 Kb (HPO42-) = = Kw Ka(H2PO4-) = 1 x 10-14 6.2 x 10-8 = 1.6 x 10-7 Kb > Ka base HPO42- + H2O ⇄ H2PO4- + OH-
3. Show by calculation if NH4F is an acid or base when in water. NH4F → NH4+ + F- acid base Both have weak parents- neither will cross off! What will the salt be? Ka(NH4+) = 5.6 x 10-10 Kb (F-) = = Kw Ka(HF) = 1 x 10-14 3.5 x 10-4 = 2.9 x 10-11 Ka > Kb acid
4. Show by calculation if NH4CH3COO is an acid or base when in water. NH4CH3COO → NH4+ + CH3COO- acid base Ka(NH4+) = 5.6 x 10-10 Kb (CH3COO-) = = Kw Ka(CH3COOH) = 1 x 10-14 1.8 x 10-5 = 5.6 x 10-10 Ka = Kb neutral pH = 7.00
5. Calculate the volume of 0. 100 M H2CO3 required to. neutralize 25 5. Calculate the volume of 0.100 M H2CO3 required to neutralize 25.0 mL of 0.200 M KOH. 1H2CO3 + 2KOH → K2CO3 + 2HOH ? L 0.0250 L 0.100 M 0.200 M
5. Calculate the volume of 0. 100 M H2CO3 required to. neutralize 25 5. Calculate the volume of 0.100 M H2CO3 required to neutralize 25.0 mL of 0.200 M KOH. 1H2CO3 + 2KOH → K2CO3 + 2HOH ? L 0.0250 L 0.100 M 0.200 M 0.0250 L KOH
5. Calculate the volume of 0. 100 M H2CO3 required to. neutralize 25 5. Calculate the volume of 0.100 M H2CO3 required to neutralize 25.0 mL of 0.200 M KOH. 1H2CO3 + 2KOH → K2CO3 + 2HOH ? L 0.0250 L 0.100 M 0.200 M 0.0250 L KOH x 0.200 mol L
5. Calculate the volume of 0. 100 M H2CO3 required to. neutralize 25 5. Calculate the volume of 0.100 M H2CO3 required to neutralize 25.0 mL of 0.200 M KOH. 1H2CO3 + 2KOH → K2CO3 + 2HOH ? L 0.0250 L 0.100 M 0.200 M 0.0250 L KOH x 0.200 mol x 1 mole H2CO3 L 2 mole KOH
5. Calculate the volume of 0. 100 M H2CO3 required to. neutralize 25 5. Calculate the volume of 0.100 M H2CO3 required to neutralize 25.0 mL of 0.200 M KOH. 1H2CO3 + 2KOH → K2CO3 + 2HOH ? L 0.0250 L 0.100 M 0.200 M 0.0250 L KOH x 0.200 mol x 1 mole H2CO3 x 1 L L 2 mole KOH 0.100 mol
5. Calculate the volume of 0. 100 M H2CO3 required to. neutralize 25 5. Calculate the volume of 0.100 M H2CO3 required to neutralize 25.0 mL of 0.200 M KOH. 1H2CO3 + 2KOH → K2CO3 + 2HOH ? L 0.0250 L 0.100 M 0.200 M 0.0250 L KOH x 0.200 mol x 1 mole H2CO3 x 1 L = 0.0250 L L 2 mole KOH 0.100 mol
6. Label the equation that has a Ka, Kb, Ksp, Kw, or Keq. Mg(OH)2(s) ⇌ Mg2+ + 2OH- CN- + H2O ⇌ HCN + OH- NH4+ + H2O ⇌ H3O+ + NH3 N2O4(g) ⇌ 2NO2(g) 2H2O ⇌ H3O+ + OH-
6. Label the equation that has a Ka, Kb, Ksp, Kw, or Keq. Ksp Mg(OH)2(s) ⇌ Mg2+ + 2OH- CN- + H2O ⇌ HCN + OH- NH4+ + H2O ⇌ H3O+ + NH3 N2O4(g) ⇌ 2NO2(g) 2H2O ⇌ H3O+ + OH-
6. Label the equation that has a Ka, Kb, Ksp, Kw, or Keq. Ksp Mg(OH)2(s) ⇌ Mg2+ + 2OH- Kb CN- + H2O ⇌ HCN + OH- NH4+ + H2O ⇌ H3O+ + NH3 N2O4(g) ⇌ 2NO2(g) 2H2O ⇌ H3O+ + OH-
6. Label the equation that has a Ka, Kb, Ksp, Kw, or Keq. Ksp Mg(OH)2(s) ⇌ Mg2+ + 2OH- Kb CN- + H2O ⇌ HCN + OH- Ka NH4+ + H2O ⇌ H3O+ + NH3 N2O4(g) ⇌ 2NO2(g) 2H2O ⇌ H3O+ + OH-
6. Label the equation that has a Ka, Kb, Ksp, Kw, or Keq. Ksp Mg(OH)2(s) ⇌ Mg2+ + 2OH- Kb CN- + H2O ⇌ HCN + OH- Ka NH4+ + H2O ⇌ H3O+ + NH3 Keq N2O4(g) ⇌ 2NO2(g) 2H2O ⇌ H3O+ + OH-
6. Label the equation that has a Ka, Kb, Ksp, Kw, or Keq. Ksp Mg(OH)2(s) ⇌ Mg2+ + 2OH- Kb CN- + H2O ⇌ HCN + OH- Ka NH4+ + H2O ⇌ H3O+ + NH3 Keq N2O4(g) ⇌ 2NO2(g) Kw 2H2O ⇌ H3O+ + OH-