Ascorbic acid (vitamin C ) is a diprotic acid, H2 C6 H6 O6. What is the pH of a 0.10 M solution?

step 1 Hello everyone so in this question this corbic acid vitamin C is a diprotic acid H2 c6 H6 or 6 w

Ascorbic acid (vitamin C ) is a diprotic acid, H2 C6 H6 O6....

Ascorbic acid (vitamin $\mathrm{C}$ ) is a diprotic acid, $\mathrm{H}_{2} \mathrm{C}_{6} \mathrm{H}_{6} \mathrm{O}_{6}$. What is the $\mathrm{pH}$ of a $0.10 \mathrm{M}$ solution? The acid ionization constants are $K_{\mathrm{al}}=9.0 \times 10^{-5}$ and $K_{\mathrm{a} 2}=1.6 \times 10^{-12} \cdot(\log 2=0.3, \log 3=0.48)$ (a) $3.52$ (b) $2.52$ (c) $1.52$ (d) $2.48$

Ascorbic acid (vitamin $\mathrm{C}$ ) is a diprotic acid, $\mathrm{H}_{2} \mathrm{C}_{6} \mathrm{H}_{6} \mathrm{O}_{6}$. What is the $\mathrm{pH}$ of a
$0.10 \mathrm{M}$ solution? The acid ionization constants are $K_{\mathrm{al}}=9.0 \times 10^{-5}$ and $K_{\mathrm{a} 2}=1.6 \times 10^{-12} \cdot(\log 2=0.3, \log 3=0.48)$
(a) $3.52$
(b) $2.52$
(c) $1.52$
(d) $2.48$

Key Concepts

Acid Dissociation Equilibrium

This concept refers to the equilibrium established when an acid dissolves in water and ionizes to produce hydrogen ions (H?) and its conjugate base. The equilibrium constant (Ka) quantifies the extent of acid ionization, and understanding this equilibrium is essential for calculating the pH of weak acid solutions.

Diprotic Acids and Sequential Ionization

Diprotic acids, like ascorbic acid, have two ionizable hydrogen atoms and undergo two distinct dissociation steps, each with its own acid ionization constant (Ka1 and Ka2). Typically, the first dissociation step, characterized by a larger Ka, has a more significant effect on the overall pH than the second step, allowing for simplified pH calculations.

Weak Acid Approximation and Equilibrium Calculations

In calculating the pH of a weak acid solution, approximations are often used based on the assumption that the degree of ionization is small relative to the initial concentration. This simplification reduces the complexity of the mass balance and equilibrium expressions, enabling the estimation of hydrogen ion concentration and subsequent pH determination.

Logarithmic pH Scale

The pH scale is a logarithmic measure of the hydrogen ion concentration in a solution, defined as pH = -log[H?]. Understanding how to work with logarithms and approximate common logarithmic values is essential for translating equilibrium concentrations of hydrogen ions into a precise pH value.

Transcript

Please give Ace some feedback