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Calculate either [H3O+] or [OH−] for each of the solutions at 25 °C. Solution A: [OH−]=1.55×10−7 M Solution A: [H3O+]= M Solution B: [H3O+]=9.43×10−9 M Solution B: [OH−]= M Solution C: [H3O+]=0.000775 M Solution C: [OH−]= M Which of these solutions are basic at 25 °C? Solution C: [H3O+]=0.000775 M Solution A: [OH−]=1.55×10−7 M Solution B: [H3O+]=9.43×10−9 M

Respuesta :

Answer: A. [tex][H_3O^+]=0.64\times 10^{-7}M[/tex]

B. [tex][OH^-]=0.11\times 10^{-5}M[/tex]

C. [tex][OH^-]=\frac{10^{-14}}{0.000775}=1.3\times 10^{-11}M[/tex]

Thus solution B is basic in nature.

Explanation:

pH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

pH for acidic solutions is less than 7, for basic solutions it is more than 7 and for neutral solutions it is equal to 7.

[tex]pH=-\log [H^+][/tex]

[tex]pOH=-log[OH^-][/tex]

[tex]pH+pOH=14[/tex]

or [tex][H^+][OH^-]=10^{-14}[/tex]

A. [tex][OH^-]=1.55\times 10^{-7}M[/tex]

[tex][H_3O^+]=\frac{10^{-14}}{1.55\times 10^{-7}}=0.64\times 10^{-7}M[/tex]

[tex]pH=-log[H_3O^+]=-log[0.64\times 10^{-7}]=7[/tex]

B. [tex][H_3O^+]=9.43\times 10^{-9}M[/tex]

[tex][OH^-]=\frac{10^{-14}}{9.43\times 10^{-9}}=0.11\times 10^{-5}M[/tex]

[tex]pH=-log[H_3O^+]=-log[9.43\times 10^{-9}]=8[/tex]

C. [tex][H_3O^+]=0.000775M[/tex]

[tex][OH^-]=\frac{10^{-14}}{0.000775}=1.3\times 10^{-11}M[/tex]

[tex]pH=-log[H_3O^+]=-log[0.000775]=3[/tex]

Thus solution B is basic.

dsdrajlin

[H₃O⁺] or [OH⁻] at 25 °C are:

  • Solution A: [H₃O⁺] = 6.45 × 10⁻⁸ M (Basic)
  • Solution B: [OH⁻] = 1.06 × 10⁻⁶ M (Basic)
  • Solution C: [OH⁻] = 1.29 × 10⁻¹¹ M (Acid)

Classification of solutions according to [H₃O⁺]

  • If [H₃O⁺] > 10⁻⁷ M, the solution is acid.
  • If [H₃O⁺] = 10⁻⁷ M, the solution is neutral.
  • If [H₃O⁺] < 10⁻⁷ M, the solution is basic.

We have to calculate either [H₃O⁺] or [OH⁻]. They are related through the following expression.

[H₃O⁺][OH⁻] = 10⁻¹⁴

  • Solution A: [OH⁻] = 1.55×10⁻⁷ M

[H₃O⁺] = 10⁻¹⁴/1.55×10⁻⁷ = 6.45 × 10⁻⁸ M

The solution is basic.

  • Solution B: [H₃O⁺] = 9.43×10⁻⁹ M

[OH⁻] = 10⁻¹⁴/9.43×10⁻⁹ = 1.06 × 10⁻⁶ M

The solution is basic.

  • Solution C: [H₃O⁺] = 0.000775 M

[OH⁻] = 10⁻¹⁴/0.000775 = 1.29 × 10⁻¹¹ M

The solution is acid.

[H₃O⁺] or [OH⁻] at 25 °C are:

  • Solution A: [H₃O⁺] = 6.45 × 10⁻⁸ M (Basic)
  • Solution B: [OH⁻] = 1.06 × 10⁻⁶ M (Basic)
  • Solution C: [OH⁻] = 1.29 × 10⁻¹¹ M (Acid)

Learn more about basicity here: https://brainly.com/question/172153

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