Question

5. Label each of the following aqueous species as being a strong base, a weak base, or a species with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is strong, weak, or a species with negligible acidity. Draw Lewis structures for all species, including formal charges. (a) CH3C02- (acetate ion) (b) NH3 (c) 02- (d) HS-

Help please and show all work!

Answer 1

Basicity of CH3CO₂^-

CH3CO₂^- is a weak base. The reason for its weakest basicity rely on its position of its conjugate acid. As the acetate ion 's conjugate acid reside under H₂O. It is a condition, that a conjugate acid of a base lies below H₂O strong.

Basicity of NH₃

Nitrogen atom in NH₃ accepts a protons, because it has an electron pair. This fact show it is a weak base. Ammonia attracts hydrogen ions and ammonium ions while dissolving in water, leads to the formation of hydrogen ions and ammonium ions.

Basicity of O₂^-

Charge of Oxide ion is very high, whereas it is very small in size. This evident is sufficient to prove it is a very strong base. In addition it has a significant reaction with water to form hydroxide ions.

Basicity of HS^-

HS^- has the capability of attracting a proton. It is concluded as that it is a moderate weak Bronsted - Lowry base.

Conjugate acid of CH3CO₂^-and its acidity character

It's Conjugate acid is CH3COOH ie., Acetic Acid. Acidity can be mentioned for the Acetic Acid as a Weak Acid.

It has the pH value of 2.4 and the pKa value as 4.76.

Conjugate acid of NH₃and its acidity character

Conjugate acid for Ammonia is Ammonium NH₄⁺ . Dissolution in water takes place by the transfer of a proton from water to the base, leads to the formation of Ammonium, a conjugate acid of NH₃ and a hydroxide ion. It possess the Weak acid character

Conjugate acid of O₂^-and its acidity character

OH^- is the Conjugate acid of O₂^- . It has a negative acidic character. If the solution contains OH^- then the solution is basic.

Conjugate acid of HS^-and its acidity character

Hydrogen Sulphide H₂S is a Conjugate acid of HS^- . After dissolution in water there is a formation of a very weak dibasic acid, which is otherwise called Hydrosulphuric acid.

Lewis Structure for CH3CO₂^-

H:C: C :0: I:U 0:0 CH3co Cacetate ion)

Lewis Structure of NH₃

_{H-N-H za NH3 (Ammonia)}

Lewis Structure of O^2-

Oxide ion o

Lewis Structure of HS^-

HS Hydro sulphide ion