Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?a. 4.0 Mb. 10−10Mc. 10−4Md. 104M

Verified step by step guidance

1. Understand that pH is a measure of the hydrogen ion concentration in a solution, defined as pH = -\log_{10}[H^+].
2. Given that the pH of the lake is 4.0, set up the equation: 4.0 = -\log_{10}[H^+].
3. To find the hydrogen ion concentration [H^+], rewrite the equation in exponential form: [H^+] = 10^{-4.0}.
4. Recognize that the expression 10^{-4.0} represents the hydrogen ion concentration in moles per liter (M).
5. Compare the calculated hydrogen ion concentration with the given options to identify the correct answer.

Key Concepts

pH Scale

The pH scale measures the acidity or alkalinity of a solution, ranging from 0 to 14. A pH of 7 is neutral, while values below 7 indicate acidity and above 7 indicate alkalinity. Each unit change in pH represents a tenfold change in hydrogen ion concentration, making it crucial for understanding the relationship between pH and ion concentration.

Hydrogen Ion Concentration

Hydrogen ion concentration, expressed in moles per liter (M), quantifies the amount of H+ ions in a solution. It is directly related to pH, where the formula [H+] = 10^(-pH) allows for the calculation of hydrogen ion concentration from pH values. For example, a pH of 4.0 corresponds to a hydrogen ion concentration of 10^(-4) M.

Logarithmic Relationship

The relationship between pH and hydrogen ion concentration is logarithmic, meaning that small changes in pH result in significant changes in H+ concentration. This is important for calculations involving pH, as it requires understanding that each unit decrease in pH increases the hydrogen ion concentration by a factor of ten, which is essential for solving the given question.