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Ch. 3 - Water and Life
Campbell - Campbell Biology 12th Edition
Urry12th EditionCampbell BiologyISBN: 9785794169850Not the one you use?Change textbook
All textbooksUrry 12th EditionCh. 3 - Water and LifeProblem 4
Chapter 3, Problem 4

What is the hydroxide ion concentration of the lake described in question 3?
a. 10⁻¹⁰ M
b. 10⁻⁴ M
c. 10⁻⁷ M
d. 10.0 M

Verified step by step guidance
1
Identify the pH of the lake from question 3, as the hydroxide ion concentration is related to the pH value.
Recall the relationship between pH and pOH: \( \text{pH} + \text{pOH} = 14 \). Use this equation to find the pOH if the pH is known.
Use the formula \( \text{pOH} = -\log[\text{OH}^-] \) to calculate the hydroxide ion concentration \([\text{OH}^-]\).
Convert the pOH value to the hydroxide ion concentration using the inverse logarithmic function: \([\text{OH}^-] = 10^{-\text{pOH}}\).
Compare the calculated hydroxide ion concentration with the given options (a, b, c, d) to determine the correct answer.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

pH and pOH Relationship

The pH and pOH of a solution are related through the equation pH + pOH = 14 at 25°C. This relationship helps determine the concentration of hydroxide ions if the pH is known. Understanding this concept is crucial for calculating the hydroxide ion concentration from the given options.
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Hydroxide Ion Concentration

Hydroxide ion concentration is a measure of the amount of OH− ions present in a solution. It is expressed in molarity (M), which indicates moles per liter. Calculating this concentration involves understanding the dissociation of water and the balance between H+ and OH− ions in a solution.
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Water Ionization Constant (Kw)

The ionization constant of water (Kw) is 1.0 x 10^-14 at 25°C, representing the product of the concentrations of H+ and OH− ions in pure water. This constant is essential for calculating either ion concentration when the other is known, using the formula [H+][OH−] = Kw.
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Related Practice
Textbook Question

Which of the following is a hydrophobic material?

a. Paper

b. Table salt

c. Wax

d. Sugar

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We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

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c. Number of atoms

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Textbook Question

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

a. 4.0 M

b. 10¹⁰M

c. 10⁴M

d. 104M

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Textbook Question

A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.)

a. 50°C

b. 5°C

c. 100°C

d. 10°C

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Textbook Question

Draw the hydration shells that form around a potassium ion and a chloride ion when potassium chloride (KCl) dissolves in water. Label the positive, negative, and partial charges on the atoms.

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