DuckieDai Nernst Equation Python Program

chemistry · MIT License

Overview

Calculate reaction or cell potential from E0, temperature, electron count, and reaction quotient using the general or 298 K Nernst form.

Not calculator tested
Downloaded 36 times
Version 1.0.0
944 bytes
Uses math

Download nerns.py Read the source How to install

Before you run it

TI-84 Plus CE Python · No calculator OS or Python App version has been verified.
TI Connect CE .py transfer is the intended path; calculator OS, Python App, transfer, and execution have not yet been tested for this release
E0, Q, and n refer to the same balanced reaction and electron-transfer convention.
Concentrations or partial pressures approximate activities only when that course approximation is appropriate.
T, n, and Q are positive; the 0.0592 V shortcut is fixed to approximately 298 K.

Try the DuckieDai calculator screen

Follow the same opening, solve menu, prompts, validation, and result flow as the downloadable program.

JavaScript is required for the optional browser simulation. Source viewing and downloading remain available without it.

Simulation boundary: This preview uses a reviewed browser adapter. It does not execute the downloaded Python and does not prove TI-Python or calculator compatibility.

Learn the math

How the Nernst equation works

The idea

A cell's voltage depends on the concentrations of what is reacting. The Nernst equation corrects the standard cell potential for conditions that are not standard.

When the reaction quotient Q is less than 1 the voltage is higher than standard; when Q is greater than 1 it is lower.

The formula

E = E0 - (R*T/(n*F))*ln(Q)

E = E0 - (0.0592/n)*log10(Q) at 298 K

E: cell potential under the stated conditions (V)
E0: standard cell potential (V)
n: moles of electrons transferred
Q: reaction quotient
T: temperature in kelvin

Using the program

Choose 1 to enter any temperature, or 2 to use 298 K.
Enter E0, the number of electrons, and Q.
The program shows E, the size of the correction, and whether the cell is spontaneous.

Worked example

A zinc-copper cell has E0 = 1.10 V and transfers 2 electrons. With Q = 0.01 at 298 K, choose 2 and enter 1.10, 2, and 0.01.

E = 1.10 - (0.0592/2) x log10(0.01)

The program shows E volts = 1.1592 and Spontaneous cell.

Tips and common mistakes

Q uses the same form as the equilibrium expression: products over reactants, leaving out solids and pure liquids.
n comes from the balanced half-reactions, not from the coefficients alone.
At equilibrium E is 0 and Q equals K.

Where this comes up

It appears in the electrochemistry unit of general chemistry, usually second semester, and in analytical chemistry. Biology and physiology courses use the same equation for membrane potentials.

Exact reviewed bytes

Source code

Download .py

View source below, copy it when JavaScript is available, or download the exact .py bytes.

from math import log
def intro(n):
 print("+----------------------+");print("| "+n+" |");print("|   ___(o )> quack!    |");print("|   by DuckieDai       |");print("+----------------------+");input("ENTER to start: ")
def num(s):
 while 1:
  try:return float(input(s))
  except:print("Enter a number")
def pos(s):
 while 1:
  x=num(s)
  if x>0:return x
  print("Must be positive")
def pick():
 while 1:
  q=input("1 Any temp 2 298K: ")
  if q=="1" or q=="2":return q
  print("Choose 1 or 2")
intro("NERNST EQUATION")
q=pick();e0=num("E0 volts: ");n=pos("Electrons n: ");Q=pos("Q: ")
if q=="1":
 t=pos("Temp K: ");cor=8.314*t*log(Q)/(n*96485)
else:cor=.0592*log(Q,10)/n
e=e0-cor;print("E volts =",e);print("Correction =",cor)
if e>0:print("Spontaneous cell")
elif e<0:print("Nonspontaneous as written")
else:print("At equilibrium")
input("ENTER for guide: ");print("Q<1 raises E; Q>1 lowers E");print("DuckieDai: done!");input("ENTER to exit: ")

from math import log
def intro(n):
print("+----------------------+");print("| "+n+" |");print("| ___(o )> quack! |");print("| by DuckieDai |");print("+----------------------+");input("ENTER to start: ")
def num(s):
while 1:
try:return float(input(s))
except:print("Enter a number")
def pos(s):
while 1:
x=num(s)
if x>0:return x
print("Must be positive")
def pick():
while 1:
q=input("1 Any temp 2 298K: ")
if q=="1" or q=="2":return q
print("Choose 1 or 2")
intro("NERNST EQUATION")
q=pick();e0=num("E0 volts: ");n=pos("Electrons n: ");Q=pos("Q: ")
if q=="1":
t=pos("Temp K: ");cor=8.314*t*log(Q)/(n*96485)
else:cor=.0592*log(Q,10)/n
e=e0-cor;print("E volts =",e);print("Correction =",cor)
if e>0:print("Spontaneous cell")
elif e<0:print("Nonspontaneous as written")
else:print("At equilibrium")
input("ENTER for guide: ");print("Q<1 raises E; Q>1 lowers E");print("DuckieDai: done!");input("ENTER to exit: ")

Filename: nerns.py
Size: 944 bytes
SHA-256: 57028fdd4585b6c2ba7bab533ea95c8d990a15e5b7dac74eaf37cbdea5504d1b

Usage

Inputs

Standard potential E0 in volts
Positive absolute temperature and positive integer electron count
Positive dimensionless reaction quotient Q

Outputs

Potential and logarithmic correction in volts
Conditional cell-voltage interpretation

Units: Potential is volts, temperature is kelvin, Q is dimensionless and activity-based, R is 8.314 J/(mol*K), and F is 96485 C/mol.

Assumptions and limitations

Assumptions

E0, Q, and n refer to the same balanced reaction and electron-transfer convention.
Concentrations or partial pressures approximate activities only when that course approximation is appropriate.

Constraints

T, n, and Q are positive; the 0.0592 V shortcut is fixed to approximately 298 K.

Known failures

A half-cell potential alone does not establish overall cell spontaneity without a complete reaction convention.
Using dimensional concentrations directly in Q or inconsistent reaction scaling changes the result.

Compatibility and review

Review status: Not calculator tested
Tested on: The owner reports personally testing the supplied archive programs on a calculator; exact model, OS, and Python App versions were not recorded
What happened: Owner reported interactive testing is disclosed, but the published bytes are not labeled independently calculator tested because the environment is unrecorded and Arrhenius received a narrow intake correction
Dependencies: math
Suggested calculator name: NERNS — you can give it another valid, unique name when you transfer it
Desktop test cases: Not available for this interactive-only source

This exact source auto-launches an interactive calculator session, so compatibility evidence comes from the recorded physical-device review rather than an importable desktop fixture.

Transfer and launch

Download the .py file, send it to your calculator with TI Connect CE as NERNS or another name, then open the Python App and try the worked example on this page first. This release has no verified calculator OS or Python App version; treat transfer and execution as unverified until independently tested.

Full installation and troubleshooting guide. Check your teacher's or exam's rules before using any program.

Version history

1.0.0 — current version, published 2026-09-23. Download this reviewed version

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