McCord - Exam 4

Exam 4 - Electrochemistry

Wed 5/3 7-9pm

Results

Average 50375: 78.42

Avegage 50380: 77.71

ALL Average: 78.04

Median: 81

Std Dev: 13.42

Total 100's: 2

What the Student Brings to Exams

official UT ID card (with your picture and name on it)
a simple scientific calculator (not a graphing calculator)
a pencil(s) and eraser
memorized formulas in your head - not on paper or anything else
nothing else is allowed

What we provide for the Exams

A printed copy of the exam (every exam has a unique version number on it).
An answer sheet for the exam. This is a bubblesheet for your answers.
An exam cover page that has ALL needed conversion factors and data. No formulas will be given.
A periodic table of the elements with symbols, atomic number, and atomic weights.

What Formulas & Concepts the Student Should Memorize

Concepts

reduction = the gain of electrons (ox# decreases)

oxidation = the loss of electrons (ox# increases)

cathode = the electrode where reduction occurs red cat

anode = the electrode where oxidation occurs an ox

anode $\bigl|$ anodic solution $\bigl|\bigl|$ cathodic solution $\bigl|$ cathode

Formulas

$E^\circ_{\rm cell} = E^\circ_{\rm cathode} - E^\circ_{\rm anode}$

$\Delta G^\circ = -nFE^\circ$

$\Delta G^\circ = -RT\ln K$

$nFE^\circ = RT \ln K$

$E = E^\circ - {RT\over nF}\ln Q$

$E = E^\circ - {0.05916\over n}\log Q$

$\displaystyle{I\cdot t\over n\cdot F} = {\rm moles}$

What we provide on the exam cover page or additional handout page

Periodic Table

Constants (such as...)
- F = 96485 C/mol e^–
- R = 8.314 J/mol K
- R = 0.08206 L atm/mol K

Table of Standard Potentials
Conversion factors

Learning Outcomes for Electrochemistry

Students will be able to...

Identify an oxidation – reduction (redox) reaction based on changes in oxidation numbers across the chemical change.
Identify oxidizing/reducing agents in chemical reaction.
Completely balance a redox reaction in acidic or basic solution.
Recognize degrees of reactivity based on an activity series or a standard potential table.
Apply standard potential data to determine the relative strength of oxidizing and reducing agents.
Construct an electrochemical cell diagram or drawing which includes the identification of the anode, cathode, and salt bridge from either a redox reaction or from the short hand cell notation.
Show the direction of electron flow, the sign of the electrodes, the direction of ion flow in the salt bridge, on a given cell diagram or drawing.
Describe the standard hydrogen electrode (SHE) and state its function.
Apply standard potential data ( $E^\circ$ ) to calculate the standard cell potential ( $E^\circ_{\rm cell}$ ) for an electrochemical cell and from the sign of the potential predict if the cell is voltaic or electrolytic.
Calculate the cell potential for a nonstandard cell.
Describe fully the relationship between the standard free energy ( $\Delta G^\circ$ ) and the standard cell potential ( $E^\circ$ ).
Describe fully the relationship between standard cell potential ( $E^\circ$ ) and the equilibrium constant ( $K$ ).
Explain thermodynamically the operation of a concentration cell, and be able to predict the concentration in the cell based on the measured cell potential.
Understand the relationship between the quantity of charge delivered or produced (coulombs) and the amount of reactant used or product formed (moles) for both voltaic and electrolytic cells.
Describe the basic principles of battery design and function.
Identify the differences and similarities of the three fundamental types of batteries: primary cells, secondary cells, and fuel cells.
Know the details of the chemical reactions used in a lead-acid battery.
Know the reaction chemistry (reactants and products) of an alkaline battery (cell)