Using the Thermodynamic Data Provided Below, Calculate K_a for HCN(aq) $\circ$

question 41

Multiple Choice

Using the thermodynamic data provided below, calculate K_a for HCN(aq) at 25 ^$\circ$ . $\begin{array}{|l|c|c|}\hline & \Delta \mathrm{H}^\circ_{\mathrm{f}}(\mathrm{~kJ} / \mathrm{mol}) & \mathrm{S}^{\circ}(\mathrm{J} / \mathrm{K} \cdot \mathrm{~mol}) \\\hline \mathrm{H}^{+}(a q) & 0 & 0 \\\hline \mathrm{CN}^{-}(a q) & 151.0 & 117.99 \\\hline \mathrm{HCN}(a q) & 105.4 & 128.9 \\\hline\end{array}$

• A) 2.4 * 10^-9
• B) 2.6 * 10^-9
• C) 2.8 * 10^-9
• D) 3.0 * 10^-9
• E) None of the above

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Definitions:

Return on Common Stockholders' Equity

A measure of financial performance that indicates how much profit a company generates with the money shareholders have invested, specifically for common shares.

Preferred Dividends

Dividends that are paid to preferred shareholders before any are distributed to common shareholders.

Earnings per Share

A measure of a company's profitability that indicates how much money shareholders would receive for each share owned, calculated by dividing net income by the number of outstanding shares.

Interest Expense

The cost incurred by an entity for borrowed funds, reflected as a charge in the income statement.