Using the Thermodynamic Data Provided Below, Calculate K_a2 for H₂CO₃(aq) $\circ$

question 121

Multiple Choice

Using the thermodynamic data provided below, calculate K_a2 for H₂CO₃(aq) at 25 ^$\circ$ . $\begin{array}{|l|c|c|}\hline & \Delta \mathrm{H}_{\mathrm{f}}^{\circ}(\mathrm{kJ} / \mathrm{mol}) & \mathrm{S}^{\circ}(\mathrm{J} / \mathrm{K} \cdot \mathrm{~mol}) \\\hline \mathrm{H}^{+}(a q) & 0 & 0 \\\hline \mathrm{H}_{2} \mathrm{CO}_{3}(a q) & -698.7 & 191 \\\hline \mathrm{HCO}_{3}^{-}(a q) & -691.11 & 95.0 \\\hline \mathrm{CO}_{3}^{2-}(a q) & -676.26 & -53.1 \\\hline\end{array}$

• A) 4.09 * 10^-11
• B) 4.39 * 10^-9
• C) 4.59 * 10^-10
• D) 4.59 * 10^-11
• E) None of the above

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Definitions:

Cremaster Muscle

A muscle that covers the testis and spermatic cord, involved in the reflex action of moving the testis closer to the body in response to cold or fear.

Vas Deferens

The duct that conveys sperm from the testicle to the urethra.

Spermatic Cord

A bundle of fibers and tissues in males that includes the vas deferens, blood vessels, nerves, and the cremaster muscle, responsible for supporting the testes.

Inguinal Canal

A passage in the lower anterior abdominal wall which in men, contains the spermatic cord and in women, the round ligament of uterus.