Skip to main content
Ch.20 - Electrochemistry
Tro - Chemistry: A Molecular Approach 6th Edition
Tro6th EditionChemistry: A Molecular ApproachISBN: 9780137832217Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testoTro 6th EditionCh.20 - ElectrochemistryProblema 131
Capitolo 20, Problema 131

A current of 11.3 A is applied to 1.25 L of a solution of 0.552 M HBr converting some of the H+ to H2(g), which bubles out of solution. What is the pH of the solution after 73 minutes?

Guida verificata passo dopo passo
1
Determine the initial moles of HBr in the solution using the formula: \( \text{moles} = \text{molarity} \times \text{volume} \).
Calculate the total charge passed through the solution using the formula: \( Q = I \times t \), where \( I \) is the current in amperes and \( t \) is the time in seconds.
Use Faraday's laws of electrolysis to find the moles of \( H^+ \) converted to \( H_2 \) gas. The number of moles of electrons is equal to \( \frac{Q}{F} \), where \( F \) is Faraday's constant (96485 C/mol).
Subtract the moles of \( H^+ \) converted to \( H_2 \) from the initial moles of \( H^+ \) to find the remaining moles of \( H^+ \) in the solution.
Calculate the new concentration of \( H^+ \) ions and use the formula \( \text{pH} = -\log[H^+] \) to find the pH of the solution.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
6m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Electrolysis

Electrolysis is a chemical process that uses an electric current to drive a non-spontaneous reaction. In this context, the current applied to the HBr solution causes the reduction of H+ ions to form hydrogen gas (H2), which escapes as bubbles. Understanding electrolysis is crucial for determining how much H+ is converted and how it affects the solution's pH.
Video consigliato:
Percorso guidato
01:21
The Electrolytic Cell

Molarity and Stoichiometry

Molarity (M) is a measure of concentration defined as moles of solute per liter of solution. In this problem, the initial concentration of HBr is 0.552 M, which helps calculate the number of moles of H+ present. Stoichiometry allows us to relate the amount of H+ converted to H2 gas during electrolysis, which is essential for determining the change in pH.
Video consigliato:
Percorso guidato
03:10
Solution Stoichiometry

pH Calculation

pH is a logarithmic scale used to specify the acidity or basicity of a solution, calculated as pH = -log[H+]. As H+ ions are converted to H2 gas, the concentration of H+ decreases, leading to an increase in pH. Understanding how to calculate pH based on changes in H+ concentration is vital for solving the problem.
Video consigliato:
Percorso guidato
02:15
pH Calculation Example
Pratica correlata
Domanda del libro di testo

A metal forms the fluoride MF3. Electrolysis of the molten fluo- ride by a current of 3.86 A for 16.2 minutes deposits 1.25 g of the metal. Calculate the molar mass of the metal.

736
views
Domanda del libro di testo

A sample of impure tin of mass 0.535 g is dissolved in strong acid to give a solution of Sn2+. The solution is then titrated with a 0.0448 M solution of NO3–, which is reduced to NO(g). The equivalence point is reached upon the addition of 0.0344 L of the NO3– solution. Find the percent by mass of tin in the original sample, assuming that it contains no other reducing agents.

939
views
1
rank
Domanda del libro di testo

To what pH should you adjust a standard hydrogen electrode to get an electrode potential of -0.122 V? (Assume that the partial pressure of hydrogen gas remains at 1 atm.)

707
views
Domanda del libro di testo

An MnO2(s)/Mn2+(aq) electrode in which the pH si 10.24 is prepared. Find the [Mn2+] necessary to lower the potential of the half-cell to 0.00 V (at 25°C)

889
views