What is the pH of a 0.048 M solution of hydrochloric acid ([tex]H^+[/tex])?
A. 0.32
B. 4.80
C. -0.758
D. none of these available choices
E. 1.32
Answer (2)
The pH of a 0.048 M solution of hydrochloric acid (HCl) is approximately 1.32. This is determined using the formula p H = − lo g 10 ([ H + ]) . Therefore, the correct answer is option E, 1.32.
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Recognize that HCl is a strong acid and completely dissociates, so [ H + ] = 0.048 M.
Apply the pH formula: p H = − lo g 10 [ H + ] .
Substitute the concentration: p H = − lo g 10 ( 0.048 ) .
Calculate the pH value: p H ≈ 1.32 .
Explanation
Problem Analysis We are given a 0.048 M solution of hydrochloric acid (HCl). We need to find the pH of this solution.
Understanding HCl Dissociation HCl is a strong acid, which means it completely dissociates in water to produce H + ions. Therefore, the concentration of H + ions in the solution is equal to the concentration of the HCl solution.
Determining [ H + ] The concentration of H + ions, denoted as [ H + ] , is 0.048 M.
pH Formula The pH of a solution is calculated using the formula: p H = − lo g 10 [ H + ]
Calculating pH Substitute the value of [ H + ] into the formula: p H = − lo g 10 ( 0.048 ) Calculating the pH: p H ≈ 1.3187587626244128 Rounding to two decimal places, we get: p H ≈ 1.32
Final Answer Therefore, the pH of the 0.048 M HCl solution is approximately 1.32.
Examples
The concept of pH is widely used in various fields such as environmental science, medicine, and agriculture. For example, in environmental science, monitoring the pH of water bodies helps assess water quality and the impact of pollutants. In medicine, maintaining the pH balance of blood is crucial for proper bodily functions. In agriculture, the pH of soil affects nutrient availability for plants, influencing crop growth and yield. Understanding pH and its calculation is essential for addressing real-world problems in these fields.
