What is the concentration of HCO₃^- in a 0.010 M solution of carbonic acid,H₂CO₃? For carbonic acid,Ka₁ = 4.2 × 10^-7 and Ka₂ = 4.8 × 10^-11. A)6.5 × 10^-5 M B)1.0 × 10^-2 M C)3.2 × 10^-5 M D)4.8 × 10^-11 M E)4.2 × 10^-7 M

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Quizplus · Accepted Answer

The concentration of $\text{HCO}_3^-$ in a 0.010 M solution of carbonic acid can be found using the first dissociation constant ($K_{a1} = 4.2 \times 10^{-7}$). Assuming the concentration of $\text{HCO}_3^-$ equals the concentration of $H^+$ ions produced in the first dissociation step and ignoring the second dissociation due to its much smaller $K_{a2}$, we can set up the equation $K_{a1} = \frac{x^2}{0.010 - x}$, where $x$ is the concentration of $\text{HCO}_3^-$. Given the small $K_{a1}$, $x$ can be approximated without significantly affecting the initial concentration of carbonic acid. Solving this equation yields a concentration of $\text{HCO}_3^-$ close to $6.5 \times 10^{-5}$ M.

What Is the Concentration of HCO3- in a 0

What Is the Concentration of HCO₃^- in a 0