What is the pH of a 0.35 M solution of sodium azide? The K_a value for hydrazoic acid is 1.9 $\times$ 10^-5.

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Quizplus · Accepted Answer

Sodium azide (NaN3) dissociates in water to form azide ions (N3-) and sodium ions (Na+). The azide ions then react with water to form hydrazoic acid (HN3) and hydroxide ions (OH-), which makes the solution basic. The $K_a$ for hydrazoic acid is $1.9 \times 10^{-5}$, but we're interested in the basic reaction, so we use the $K_b$ of azide ions. $K_w = K_a \times K_b$, where $K_w = 1.0 \times 10^{-14}$. Thus, $K_b = \frac{1.0 \times 10^{-14}}{1.9 \times 10^{-5}} = 5.26 \times 10^{-10}$. Using the $K_b$ and the concentration of azide ions, we can calculate the $pOH$ and then the $pH$ of the solution. The calculation shows that the pH is basic, and among the options given, 9.13 is the correct basic pH value that aligns with the expected outcome of this calculation.

What Is the PH of a 0 ×\times× 10-5

What Is the PH of a 0 $\times$ 10^-5