Calculating pH and Hydrogen Ion Concentration Quiz
18 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the relationship between pH and pOH values in a solution?

  • pH + pOH = 7
  • Their product is always 14 (correct)
  • They are equal to each other
  • The sum of pH and pOH is always 14

    • Which indicator is commonly used in pH paper to determine the pH of a solution?

  • Flavin (correct)
  • Methyl orange
  • Bromothymol blue
  • Phenolphthalein

    • How does a pH meter determine the pH of a solution?

  • By interpreting electrical signals from a probe (correct)
  • By titrating the solution
  • By analyzing the color change of the solution
  • By measuring the volume of the solution

    • According to Brønsted-Lowry theory, what defines an acid?

    <p>Any species that can donate a proton</p> Signup and view all the answers

    How would you calculate the pH of a solution if provided with the hydrogen ion concentration in moles per liter?

    <p>$pH = -log[H^+]$</p> Signup and view all the answers

    According to Lewis theory, what is a characteristic of a base?

    <p>Can accept an electron pair</p> Signup and view all the answers

    What does a pH greater than 7 indicate in a solution?

    <p>Basic solution</p> Signup and view all the answers

    How does the H+ ion concentration change when the pH decreases?

    <p>It increases</p> Signup and view all the answers

    What is the function of flavin in pH paper?

    <p>Turns red in acidic solutions</p> Signup and view all the answers

    What is used as an indicator in pH paper?

    <p>Flavin</p> Signup and view all the answers

    Which method is more accurate for measuring pH than pH paper?

    <p><strong>pH meter</strong></p> Signup and view all the answers

    What does a pH of 2 indicate about a solution?

    <p><strong>Highly acidic</strong></p> Signup and view all the answers

    What is the relationship between pH and pOH in a water solution at 25°C?

    <p>pH + pOH = 14</p> Signup and view all the answers

    What is the hydroxide ion concentration in a solution with a pOH of 9.25?

    <p>$1.78 \times 10^{-10}$ M</p> Signup and view all the answers

    How can the hydrogen ion concentration be calculated from the pH of a solution?

    <p>[H+] = $10^{pH}$</p> Signup and view all the answers

    What is the pH of a solution with a hydrogen ion concentration of $3.00 \times 10^{-8}$ M?

    <p>7.52</p> Signup and view all the answers

    If a solution has a pH of 3.89, what is its hydroxide ion concentration?

    <p>$1.26 \times 10^{-11}$ M</p> Signup and view all the answers

    What is the pOH of a solution with a hydroxide ion concentration of $5.62 \times 10^{-6}$ M?

    <p>$7.25$</p> Signup and view all the answers

    Study Notes

    pH and pOH

    • Acidity and basicity of a substance are measured in terms of the molar concentration of hydrogen (H+) or hydroxide (OH-) ions, respectively.
    • pH and pOH denote the concentration of H+ and OH- ions, respectively.

    pH Scale

    • pH scale allows classification of substances based on their acidity and basicity at 25°C.
    • Substances with pH 7 are neutral, pH > 7 are basic, and pH < 7 are acidic.
    • pH has an inverse relationship with H+ ion concentration.

    Measuring pH

    • pH paper measures pH by changing color depending on H+ and OH- ion concentration.
    • pH paper is treated with flavin, an anthocyanin commonly found in red cabbages, which turns:
      • Red in acidic solutions
      • Greenish in neutral solutions
      • Purple in basic solutions
    • pH meter is a more accurate method than pH paper.
    • pH meter contains a probe with two electrodes:
      • Sensor electrode (pH 7 buffer solution)
      • Reference electrode (saturated KCl solution)

    Acid and Base Theories

    Arrhenius Theory

    • Acid: increases H+ ion concentration in aqueous solution
    • Base: increases OH- ion concentration in aqueous solution

    Brønsted-Lowry Theory

    • Acid: donates a proton (H+)
    • Base: accepts a proton
    • Conjugate acid: formed after base accepts a proton
    • Conjugate base: formed after acid donates a proton

    Lewis Theory

    • Acid: accepts a pair of non-bonding electrons
    • Base: donates a pair of non-bonding electrons
    • Acid-base complex: formed by reaction between Lewis acid and Lewis base

    Calculating pH and pOH

    • pH = - log [H+]
    • [H+] = 10^(-pH) or [H+] = antilog (-pH)
    • pOH = - log [OH-]
    • [OH-] = 10^(-pOH) or [OH-] = antilog (-pOH)

    Example Calculations

    • Calculate pH of 0.0025 M HCl solution: pH = 2.60
    • Calculate hydrogen ion concentration in a solution with pH 8.34: [H+] = 4.57 x 10^(-9) M
    • Calculate pOH of a solution with hydroxide ion concentration 4.82 x 10^(-5) M: pOH = 4.32
    • Calculate hydroxide ion concentration in a solution with pOH 5.70: [OH-] = 2.00 x 10^(-6) M

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Test your knowledge on how to calculate pH and hydrogen ion concentration in solutions using mathematical expressions. Practice solving problems involving the relationship between pH, hydrogen ion concentration, and pOH.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser