5.2.1 Calculating pH

• pH is defined as the negative logarithm of the hydrogen ion concentration.
• Match the pH range with its description:

  pH < 7 ↔️ Acidic

  pH > 7 ↔️ Basic

  pH = 7 ↔️ Neutral
• A neutral solution has a pH of 7 and a [H+] of 1 \times 10^{ - 7} M</latex>.


  True
• Order the following logarithm rules:

  1️⃣ Product Rule: log(ab) = log a + log b

  2️⃣ Quotient Rule: log(a/b) = log a - log b

  3️⃣ Power Rule: log(a^n) = n log a
• In strong acids, complete dissociation occurs, making [H+] equal to the acid concentration.
• What is the hydrogen ion concentration ([H+]) for 0.1 M CH3COOH, a weak acid with Ka = 1.8 x 10^-5?

  1.34 x 10^-3 M
• The pH of a solution with [H+] = 5 x 10^-4 M is 3.301
• Order the steps to calculate pH from [H+] using logarithm rules:

  1️⃣ Apply the pH formula: pH = -\log_{10}[H^+]

  2️⃣ Use logarithm rules to simplify the expression

  3️⃣ Calculate the pH value
• As the hydrogen ion concentration ([H+]) increases, the pH decreases.


  True
• A solution with a pH of 10 is highly basic.
• What is scientific notation used for when handling hydrogen ion concentrations?

  To simplify large or small numbers
• If the exponent in scientific notation is positive, the decimal point is moved to the left.

  False
• What is the formula for calculating pH?

  $pH =$$- \log_{10}[H^ + ]$
• As the hydrogen ion concentration increases, the pH also increases.

  False
• A solution with a low pH is considered acidic
• For a weak acid, [H+] is calculated using the formula √(**Ka** x Acid Concentration)
• What is the hydrogen ion concentration ([H+]) in a neutral solution?

  1 x 10^-7 M
• Weak acids only partially dissociate in water.


  True
• Match the logarithm rule with its expression:

  Product Rule ↔️ log(ab) = log a + log b

  Quotient Rule ↔️ log(a/b) = log a - log b

  Power Rule ↔️ log(a^n) = n log a
• The power rule in logarithms states that log(a^n) = n log a.

  True
• The product rule in logarithms states that log(ab) = log a + log b.
• What is the pH of a solution with [H+] = 1 x 10^-7 M?

  7
• The logarithm of 1 is equal to 0.

  True
• To convert from scientific notation to standard form, move the decimal point based on the exponent.
• To convert from scientific notation to standard form, you must move the decimal
• Scientific notation for hydrogen ion concentrations is used to handle values like 1 x 10^-7 M, which represents a neutral
• Match the scientific notation with its corresponding standard notation:

  2.5 x 10^3 ↔️ 2500

  1 x 10^-7 ↔️ 0.0000001
• Weak acids undergo complete dissociation in solution.

  False
• The pH of a strong acid is calculated using the formula $pH =$$- \log_{10}[H^ + ]$


  True
• Steps to calculate the pH of a solution with a known [H+]

  1️⃣ Identify the [H+] value

  2️⃣ Apply the formula $pH =$$- \log_{10}[H^ + ]$

  3️⃣ Calculate the logarithm of [H+]

  4️⃣ Multiply by -1 to find the pH
• A solution with [H+] = 5 x 10^-4 M has a pH of approximately 3.301.


  True
• The pH of a 0.1 M solution of acetic acid is approximately 2.87
• If the exponent in scientific notation is positive, you move the decimal to the right.


  True
• If the exponent in scientific notation is negative, you move the decimal to the left.


  True
• For strong acids, the hydrogen ion concentration [H+] is equal to the initial acid concentration
• Match the acid type with its dissociation and [H+] calculation:

  Strong Acid ↔️ [H+] = [Acid]

  Weak Acid ↔️ $[H^ + ] =$$\sqrt{Ka \times [Acid]}$
• A 0.1 M solution of acetic acid with a Ka of 1.8 x 10^-5 has a [H+] of approximately 1.34 x 10^-3
• To convert [H+] = 0.000001 M to scientific notation, it becomes 1 x 10^-6
• A 0.1 M solution of acetic acid has a [H+] of approximately 1.34 x 10^-3 M.


  True