For each of the pairs of bases below, choose the stronger base:
(i) NH2- or NH3
(ii) ClO3- or ClO2-
(iii) Cl3CCOO- or Cl2HCCOO-
For i) I think it is NH2-, because it has a stronger ability to attract an H+ atom to become de-ionized.
For ii) I don't know how to determine it.
For iii) I think it is Cl2HCCOO- because it has a higher H+ concentration and it is less completely protonated than Cl3CCOO-.
Sorry, for iii) I meant that I think Cl3CCOO- is the stronger base.
You might want to look up Kb or an amide vs Kb for NH3. NH3 is the stronger base. Compare Kb for each.
HClO3 and HClO2 are acids. HClO3 is the stronger acid; therefore, HClO2 is the stronger base. Compare Ka values. HClO2 has a Ka, HClO3 is a strong acid.
Cl3CCOOH is a stronger acid (due to the added Cl) than Cl2HCCOO^-; therefore, Cl2HCCOO^- is the stronger base. Look up the Ka values and compare.
So for ii) If HClO2 is the stronger base, then does that mean that ClO2 is also the stronger base?
Of HClO3 and HClO2, HClO2 is the weaker acid; therefore, ClO2^- is the stronger base.
To determine the stronger base in each pair, we need to consider the relative strengths of the conjugate acids formed when the bases accept a proton (H+).
(i) NH2- or NH3:
In this pair, NH2- is a stronger base compared to NH3. The reasoning behind this is that NH2- can readily accept a proton to form NH3, while NH3 can also accept a proton but to a lesser extent, indicating a weaker base.
(ii) ClO3- or ClO2-:
To determine the stronger base between ClO3- and ClO2-, we need to consider which base will form a weaker conjugate acid. The stronger base will have a weaker conjugate acid. However, in this case, neither ClO3- nor ClO2- will readily accept a proton to form a conjugate acid because chlorine, being a halogen, is an electron-withdrawing group. Therefore, ClO3- and ClO2- can be considered equally weak bases.
(iii) Cl3CCOO- or Cl2HCCOO-:
Here, we need to compare the acidity of the conjugate acids formed by accepting a proton. The stronger base will yield a weaker conjugate acid. In this case, Cl3CCOO- forms Cl3CCOOH upon accepting a proton, while Cl2HCCOO- forms Cl2HCCOOH. Since Cl3CCOOH is more acidic than Cl2HCCOOH, we can conclude that Cl3CCOO- is a stronger base compared to Cl2HCCOO-.
Remember that the relative strengths of bases can also be influenced by other factors such as resonance, electronegativity, and hybridization. However, in this case, we are considering the strength of bases solely based on the acidity of their conjugate acids.