Question 41 of 69beginner🔧 ApplyNumerical1 mark

The concentration of hydrogen ion in a sample of soft drink is 3.8×10−33.8 \times 10^{-3} M. What is its pH?

Correct Answer

2.42

Exercise: EXERCISES | Q: 6.41 | (Page 45)
For More Understanding

Explanation

The pH of a solution is calculated using the formula pH=−log⁡aH+=−log⁡{[H+]/mol L−1}\text{pH} = -\log a_{H^+} = -\log \{[H^+] / \text{mol L}^{-1}\}. Given the hydrogen ion concentration of the soft drink, we substitute the value into the formula and use logarithm properties to find the pH.

Solution Steps

  1. Step 1: Write the formula for pH.

    pH=−log⁡[H+]\text{pH} = -\log[H^+]

  2. Step 2: Substitute the given hydrogen ion concentration into the formula.

    pH=−log⁡[3.8×10−3]\text{pH} = -\log[3.8 \times 10^{-3}]

  3. Step 3: Apply the logarithm property to separate the terms.

    pH=−{log⁡[3.8]+log⁡[10−3]}\text{pH} = -\{\log[3.8] + \log[10^{-3}]\}

  4. Step 4: Substitute the logarithm values and solve.

    pH=−{(0.58)+(−3.0)}=−{−2.42}=2.42\text{pH} = -\{(0.58) + (-3.0)\} = -\{-2.42\} = 2.42
PreviousNext