Multiple Choice
Which of the following correctly completes the autoionization reaction of water and provides the expressions for its equilibrium constant (K_c) and ion product (K_w)?
40
views
17. Acid and Base Equilibrium
Auto-Ionization
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Chemistry student prepared an aqueous solution at 30ºC. If the solutions contains 7.42 × 10−9 M of hydroxide ions, calculate the pH.
A
5.703
B
8.130
C
8.300
D
5.980
Verified step by step guidance1
Start by understanding the relationship between hydroxide ions (OH⁻) and hydrogen ions (H⁺) in water. The product of their concentrations is constant at a given temperature, known as the ion product of water (Kw). At 30ºC, Kw is approximately 1.47 × 10⁻¹⁴.
Use the formula Kw = [H⁺][OH⁻] to find the concentration of hydrogen ions. Rearrange the formula to solve for [H⁺]: [H⁺] = Kw / [OH⁻].
Substitute the given concentration of hydroxide ions (7.42 × 10⁻⁹ M) and the value of Kw (1.47 × 10⁻¹⁴) into the equation to calculate [H⁺].
Once you have the concentration of hydrogen ions, use the formula for pH: pH = -log₁₀[H⁺].
Calculate the pH using the hydrogen ion concentration obtained in the previous step. This will give you the pH of the solution.
2:22mWatch next
Master Auto-Ionization and Kw with a bite sized video explanation from Jules
Start learningRelated Videos
Related Practice
Auto-Ionization practice set
Problem sets built by lead tutorsExpert video explanations