iran-konkur 2020 Q229

iran-konkur · Other · konkur-riazi_1399_specialized_old-curriculum Not Maths
229- How many of the following statements are correct?
  • The ion $\mathrm{HCO_3^-}$ is an example of amphoteric compounds.
  • The pH of an ammonium ion solution decreases.
  • In a healthy person, blood pH changes are within $0.1$ units.
  • Based on the Lewis acid-base theory, $\mathrm{SO_4^{2-}(aq)}$ is a stronger base than $\mathrm{CO_3^{2-}(aq)}$.
  • In the reaction: $\mathrm{[Fe(H_2O)_6]^{2+}(aq) \leftarrow Fe^{2+}(aq) + 6H_2O(l)}$, water plays the role of a Lewis base -- Brønsted.

(1) 2 (2) 3 (3) 4 (4) 5
\textbf{229-} How many of the following statements are correct?

\begin{itemize}
\item The ion $\mathrm{HCO_3^-}$ is an example of amphoteric compounds.
\item The pH of an ammonium ion solution decreases.
\item In a healthy person, blood pH changes are within $0.1$ units.
\item Based on the Lewis acid-base theory, $\mathrm{SO_4^{2-}(aq)}$ is a stronger base than $\mathrm{CO_3^{2-}(aq)}$.
\item In the reaction: $\mathrm{[Fe(H_2O)_6]^{2+}(aq) \leftarrow Fe^{2+}(aq) + 6H_2O(l)}$, water plays the role of a Lewis base -- Brønsted.
\end{itemize}

(1) 2 \qquad (2) 3 \qquad (3) 4 \qquad (4) 5