What is the h of 0.006 m benzoic acid?

0.006 m benzoic acid?

In chemical analysis, we often need to calculate the ion concentration of a substance in a solution. A common computational problem is how to solve for the hydrogen ion concentration (H) in a 0.006 m benzoic acid solution. Benzoic acid is a weak acid that is partially ionized in water to form hydrogen ions and benzoate ions. This article will be aimed at "0.006 m benzoic acid H is how much?" This question, carries on the detailed analysis and gives the answer.

Benzoic Acid Chemical Properties

Benzoic acid (C; H; COOH) is an organic acid with weak acid properties. When benzoic acid is dissolved in water, it is partially ionized. The chemical reaction formula is:

[ C₆H₅COOH \rightleftharpoons C₆H₅COO^- H^ ]

benzoic acid has a low degree of ionization, so the concentration of hydrogen ions generated is much lower than that of strong acids. In order to calculate its H concentration, we need to know the acidity constant (Ka) of benzoic acid, which is essential for the ionization calculation of weak acids.

Calculation of acidity constant (Ka)

The acidity constant (Ka) of benzoic acid is an important parameter to reflect the strength of the acid. For benzoic acid, Ka is approximately 6.3 × 10. The smaller the value, the weaker the benzoic acid and the lower the degree of ionization. In order to calculate the H concentration in the 0.006 m benzoic acid solution, we need to solve it with the aid of the acidity constant.

Ionization Equilibrium Establishment

For a 0.006 m benzoic acid solution, we can set the initial concentration of benzoic acid as C ^ (I. e. 0.006 mol/L). Assuming that the concentration of hydrogen ions produced by the ionization of benzoic acid in water is x, the ionized concentrations are:

• C₆H₅COOH:0.006 - x
• C₆H₅COO⁻:x
• H⁺:x

Based on the definition of the acidity constant Ka, we can establish the following equilibrium equation:

[ K_a = \frac{[C₆H₅COO^-][H^ ]}{[C₆H₅COOH]} ]

substitute known values:

[ 6.3 \times 10^{-5} = \frac{x \times x}{0.006 - x} ]

approximate calculation

In the calculation of weak acids, if the concentration of acid is much higher than the degree of ionization (I. e. the value of x is much less than 0.006), we can make an approximate assumption that 0.006 - x ≈ 0.006. This time the equation can be simplified:

[ 6.3 \times 10^{-5} = \frac{x^2}{0.006} ]

solving this equation yields:

[ x^2 = 6.3 \times 10^{-5} \times 0.006=3.78 \times 10^{-7} ]

[ x = \sqrt{3.78 \times 10^{-7}} \approx 6.15 \times 10^{-4} \, \text{mol/L} ]

thus, the H + concentration in a 0.006 m benzoic acid solution is about 6.15 × 10? mol/L.

Summary

From the above analysis, we conclude that the hydrogen ion concentration in the 0.006 m benzoic acid solution is approximately 6.15 × 10? mol/L. This calculation shows how the concentration of H can be solved by the ionization equilibrium equation based on the acidity constant and initial concentration of the weak acid. For similar problems, mastering the method of ionization constant and approximate calculation can effectively solve the problem of solving H concentration in weak acid solution.