Which classification is correct for the reaction?

H₂PO₄⁻(aq) + H₂O(l) → HPO₄²⁻(aq) + H₃O⁺(aq)

State the equation for the reaction of each substance with water.

Identify one conjugate acid-base pair in the reaction.

Identify the amphiprotic species.

Write an equation to show ammonia, NH₃, acting as a Brønsted–Lowry base and a different equation to show it acting as a Lewis base.

State the equation for the reaction of each substance with water.

Formulate an equation for the reaction of one mole of phosphoric acid with one mole of sodium hydroxide.

The hydrogencarbonate ion, produced in Equilibrium (2), can also act as an acid.

State the formula of its conjugate base.

A student working in the laboratory classified HNO₃, H₂SO₄, H₃PO₄ and HClO₄ as acids based on their pH. He hypothesized that “all acids contain oxygen and hydrogen”.

Evaluate his hypothesis.

Formulate an equation for the reaction of one mole of phosphoric acid with one mole of sodium hydroxide.

Calculate the amount, in mol, of NaOH(aq) used.

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

Which two species act as Brønsted–Lowry acids in the reaction?

H₂PO₄⁻ (aq) + OH⁻ (aq) $\rightleftharpoons$ HPO₄²⁻ (aq) + H₂O (l)

A. HPO₄²⁻ (aq) and OH⁻ (aq)

B. H₂PO₄⁻ (aq) and HPO₄²⁻ (aq)

C. HPO₄²⁻ (aq) and H₂O (l)

D. H₂PO₄⁻ (aq) and H₂O (l)

Calculate the $K_{\mathrm{b}}$ of the conjugate base of ethanoic acid using sections 2 and 21 of the data booklet.

The hydrogencarbonate ion, produced in Equilibrium (2), can also act as an acid.

State the formula of its conjugate base.

Outline why H₃PO₄/HPO₄²⁻ is not a conjugate acid-base pair.

The reaction of the hydroxide ion with carbon dioxide and with the hydrogencarbonate ion can be represented by Equations 3 and 4.

Equation (3)     OH⁻ (aq) + CO₂ (g) → HCO₃⁻ (aq)
Equation (4)     OH⁻ (aq) + HCO₃⁻ (aq) → H₂O (l) + CO₃²⁻ (aq)

Discuss how these equations show the difference between a Lewis base and a Brønsted–Lowry base.

Equation (3):

Equation (4):

Which is a Lewis acid, but not a Brønsted-Lowry acid?

A.  ${\text{BF}}_3$

B.  ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$

C.  ${\text{NH}}_3$

D.  ${\text{Cl}}^{-}$

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

Which of these acids has the weakest conjugate base?

A.  $\mathrm{HCl}$

B.  ${\mathrm{CH}}_3\mathrm{COOH}$

C.  ${\mathrm{NH}}_4\mathrm{Cl}$

D.  ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$

State the formula of the conjugate base of hypochlorous acid.

State the formula of the conjugate base of hypochlorous acid.

Which species is a Lewis acid but not a Brønsted–Lowry acid?

A.  ${\mathrm{Cu}}^{2+}$

B.  ${{\mathrm{NH}}_4}^{+}$

C.  $\mathrm{Cu}$

D.  ${\mathrm{CH}}_3\mathrm{COOH}$

Formulate two equations to show the amphiprotic nature of H₂PO₄⁻.

Formulate two equations to show the amphiprotic nature of H₂PO₄⁻.