Chemical Concept Demonstrated: Strengths of acids and their conjugate bases
Demonstration and Explanations:
1. Compare HCl, HOAc, NaCl, and NaOAc: HCl is a stronger acid than HOAc. NaCl is a weaker base than NaOAc. Stronger acids have weaker conjugate bases.
| HCl | + | NaOAc | ---> | HOAc | + | NaCl |
| stronger acid | stronger base | weaker conjugate acid | weaker conjugate base |
2. Compare HCl, NaOH, and NaCl: HCl is a stronger acid than water. NaCl is a weaker base than NaOH. Strong acids react with strong bases to form weaker acids and bases.
| HCl | + | NaOH | ---> | H2O | + | NaCl |
| stronger acid | stronger base | weaker conjugate acid | weaker conjugate base |
3. Compare NaOH, NH3, and H2O, and NH4Cl: NaOH is a stronger base than NH3. Water is a weaker acid than NH4Cl. Weaker bases have stronger conjugate acids. NH3 is a weak base, but its conjugate acid, NH4Cl, is a strong acid.
| NH4Cl | + | NaOH | ---> | H2O | + | NH3 |
| stronger acid | stronger base | weaker conjugate acid | weaker conjugate base |