Conjugate acid–base pairs Knowledge-Based Download PDF

Questions

1. 1.

   Which pair lists the conjugate acid and the conjugate base of the amphiprotic hydrogen carbonate ion, $\text{HCO}_3^-$, respectively?

   • A) $\text{CO}_3^{2-}$ and $\text{H}_2\text{CO}_3$
   • B) $\text{H}_3\text{O}^+$ and $\text{OH}^-$
   • C) $\text{H}_2\text{CO}_3$ and $\text{CO}_3^{2-}$
   • D) $\text{H}_2\text{CO}_3$ and $\text{OH}^-$
2. 2.

   Which of the following statements correctly describes the structural relationship between a Brønsted–Lowry acid and its conjugate base?

   • A) The conjugate base possesses one additional proton and a net charge that is one unit more positive than the parent acid.
   • B) The conjugate base possesses one additional hydroxide ion and a net charge that is one unit more negative than the parent acid.
   • C) The conjugate base possesses one fewer proton and a net charge that is one unit more negative than the parent acid.
   • D) The conjugate base possesses two fewer protons and a net charge that is two units more negative than the parent acid.
3. 3.

   Which of the following pairs does not constitute a Brønsted–Lowry conjugate acid–base pair?

   • A) $\text{HNO}_3$ and $\text{NO}_3^-$
   • B) $\text{H}_2\text{SO}_4$ and $\text{HSO}_4^-$
   • C) $\text{H}_3\text{O}^+$ and $\text{OH}^-$
   • D) $\text{CH}_3\text{COOH}$ and $\text{CH}_3\text{COO}^-$
4. 4.

   Which chemical species is the conjugate acid of the hydrogen phosphate ion, $\text{HPO}_4^{2-}$?

   • A) $\text{PO}_4^{3-}$
   • B) $\text{H}_3\text{O}^+$
   • C) $\text{H}_2\text{PO}_4^-$
   • D) $\text{H}_3\text{PO}_4$
5. 5.

   In the reaction $\text{HSO}_3^-(\text{aq}) + \text{NH}_3(\text{aq}) \rightleftharpoons \text{SO}_3^{2-}(\text{aq}) + \text{NH}_4^+(\text{aq})$, which of the following represents a conjugate acid–base pair?

   • A) $\text{HSO}_3^-$ and $\text{NH}_4^+$
   • B) $\text{NH}_3$ and $\text{SO}_3^{2-}$
   • C) $\text{HSO}_3^-$ and $\text{SO}_3^{2-}$
   • D) $\text{HSO}_3^-$ and $\text{NH}_3$