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Two weak acids HX and HY have K(a) value...

Two weak acids `HX` and `HY` have `K_(a)` values `1.75 xx 10^(-5)` and `1.3 xx 10^(-5)`, respectively, at a certain temperature. An equimolar solution of mixture of two acids is parially neutralised by `NaOH`. How is the ratio of the contents of `X^(Theta)` and `Y^(Theta)` ions related to the `K_(a)` values and molarity?

A

`[(alpha)/(1-alpha)] = (1.75)/(1.3) xx [(alpha')/(1-alpha')],0`, where `alpha` and `alpha'` are ionised fractions of the acids `HX` and `HY` respectively.

B

The ratio is unrelated to the `K_(a)` values.

C

The ratio is unrelated to the molarity.

D

The ratio is unrelated to the `pH` of the solution.

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The correct Answer is:
To solve the problem, we need to analyze the dissociation of the two weak acids, HX and HY, and how their ionization degrees relate to their \( K_a \) values and the concentration of the acids in the solution. ### Step-by-Step Solution: 1. **Write the Dissociation Reactions**: - For acid HX: \[ HX \rightleftharpoons H^+ + X^- \] - For acid HY: \[ HY \rightleftharpoons H^+ + Y^- \] 2. **Define the Degree of Ionization**: - Let \( \alpha \) be the degree of ionization of HX. - Let \( \alpha' \) be the degree of ionization of HY. 3. **Concentration Relationships**: - If the initial concentration of both acids is \( C \), after ionization: - The concentration of \( H^+ \) from HX will be \( \alpha C \). - The concentration of \( X^- \) will also be \( \alpha C \). - The remaining concentration of HX will be \( C(1 - \alpha) \). - Similarly, for HY: - The concentration of \( H^+ \) from HY will be \( \alpha' C \). - The concentration of \( Y^- \) will be \( \alpha' C \). - The remaining concentration of HY will be \( C(1 - \alpha') \). 4. **Write the Expressions for \( K_a \)**: - For HX: \[ K_{a1} = \frac{[\text{H}^+][X^-]}{[HX]} = \frac{(\alpha C)(\alpha C)}{C(1 - \alpha)} = \frac{\alpha^2 C}{1 - \alpha} \] - For HY: \[ K_{a2} = \frac{[\text{H}^+][Y^-]}{[HY]} = \frac{(\alpha' C)(\alpha' C)}{C(1 - \alpha')} = \frac{\alpha'^2 C}{1 - \alpha'} \] 5. **Set Up the Ratio of \( K_a \) Values**: - Taking the ratio of the two \( K_a \) expressions: \[ \frac{K_{a1}}{K_{a2}} = \frac{\frac{\alpha^2 C}{1 - \alpha}}{\frac{\alpha'^2 C}{1 - \alpha'}} = \frac{\alpha^2 (1 - \alpha')}{\alpha'^2 (1 - \alpha)} \] 6. **Substitute the Given \( K_a \) Values**: - Given \( K_{a1} = 1.75 \times 10^{-5} \) and \( K_{a2} = 1.3 \times 10^{-5} \): \[ \frac{1.75 \times 10^{-5}}{1.3 \times 10^{-5}} = \frac{\alpha^2 (1 - \alpha')}{\alpha'^2 (1 - \alpha)} \] 7. **Conclusion**: - The ratio of the concentrations of \( X^- \) to \( Y^- \) ions can be expressed in terms of their degrees of ionization and \( K_a \) values, showing that the ratio is dependent on the \( K_a \) values and the degrees of ionization but not directly on the molarity of the solution.

To solve the problem, we need to analyze the dissociation of the two weak acids, HX and HY, and how their ionization degrees relate to their \( K_a \) values and the concentration of the acids in the solution. ### Step-by-Step Solution: 1. **Write the Dissociation Reactions**: - For acid HX: \[ HX \rightleftharpoons H^+ + X^- ...
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