226 – In the reaction $A(aq)$: $A(aq) \rightarrow D(aq) + 2X(aq) + H^+(aq)$, in a solution with 1 molar concentration of $HCl$, 2 molar $X(aq)$ and 1 molar $A(aq)$, the concentration $[A]$ is shown in the figure below. Which of the following graphs shows the pH change of this solution over time? (D has no acidic or basic character.) [Figure: Graph showing $[A]$ (mol/L) on y-axis with values 0.8, 0.6, 0.4, 0.2 and time (s) on x-axis with values 100, 200, 300, 400. The curve decreases from about 0.8 and levels off asymptotically.] [Figure: Four pH vs. time graphs labeled (1), (2), (3), (4):
Graph (1): pH starts around 5 and increases in an S-shaped curve, leveling off near 7, x-axis 0 to 300.
Graph (2): pH increases linearly from about 1 to 7, x-axis 0 to 300.
Graph (3): pH starts low and increases in a concave-up curve leveling near 7, x-axis 0 to 300.
Graph (4): pH starts around 5 and increases in a concave-down curve leveling near 7, x-axis 0 to 300.
]
\textbf{226 –} In the reaction $A(aq)$: $A(aq) \rightarrow D(aq) + 2X(aq) + H^+(aq)$, in a solution with 1 molar concentration of $HCl$, 2 molar $X(aq)$ and 1 molar $A(aq)$, the concentration $[A]$ is shown in the figure below.
Which of the following graphs shows the pH change of this solution over time?
(D has no acidic or basic character.)
\textit{[Figure: Graph showing $[A]$ (mol/L) on y-axis with values 0.8, 0.6, 0.4, 0.2 and time (s) on x-axis with values 100, 200, 300, 400. The curve decreases from about 0.8 and levels off asymptotically.]}
\textit{[Figure: Four pH vs. time graphs labeled (1), (2), (3), (4):
\begin{itemize}
\item Graph (1): pH starts around 5 and increases in an S-shaped curve, leveling off near 7, x-axis 0 to 300.
\item Graph (2): pH increases linearly from about 1 to 7, x-axis 0 to 300.
\item Graph (3): pH starts low and increases in a concave-up curve leveling near 7, x-axis 0 to 300.
\item Graph (4): pH starts around 5 and increases in a concave-down curve leveling near 7, x-axis 0 to 300.
\end{itemize}]}