We examine the following 4 constants and define each in terms of the other three, showing a clear link between different areas of physics.
Calculated Constants vs. Known Values:
Boltzmann constant (k_B)= (e_c * R) / F
Calculated: 1.380649000021918e-23 J/K
Actual: 1.380649000000000e-23 J/K
Difference: 2.192e-34
Faraday constant (F)=(e_c * R) / k_B
Calculated: 9.648533212153174e+04 C/mol
Actual: 9.648533212000001e+04 C/mol
Difference: 1.532e-06
Elementary charge (e_c)= (k_B * F) / R
Calculated: 1.602176633974565e-19 C
Actual: 1.602176634000000e-19 C
Difference: 2.544e-30
Gas constant (R)=(k_B * F) / e_c
Calculated: 8.314462617868006e+00 J/(mol⋅K)
Actual: 8.314462618000000e+00 J/(mol⋅K)
Difference: 1.320e-10
Let's perform a dimensional analysis on the derived formulas to ensure they are consistent and to gain further insights into the relationships between the constants. We will use standard SI units.
k_B (Boltzmann constant): J/K (Joules per Kelvin) = kg⋅m²⋅s⁻²⋅K⁻¹ F (Faraday constant): C/mol (Coulombs per mole) = A⋅s⋅mol⁻¹ (Ampere-seconds per mole) e_c (Elementary charge): C (Coulombs) = A⋅s (Ampere-seconds) R (Ideal Gas constant): J/(mol⋅K) (Joules per mole per Kelvin) = kg⋅m²⋅s⁻²⋅K⁻¹⋅mol⁻¹ (This is also the value for the Universal Gas Constant)
Formula for k_B: Units of (e_c × R): (A⋅s) * (kg⋅m²⋅s⁻²⋅K⁻¹⋅mol⁻¹) = kg⋅m²⋅s⁻¹⋅K⁻¹⋅mol⁻¹⋅A Units of (e_c × R) / F: (kg⋅m²⋅s⁻¹⋅K⁻¹⋅mol⁻¹⋅A) / (A⋅s⋅mol⁻¹) = kg⋅m²⋅s⁻²⋅K⁻¹ Result: The units of the calculated value for k_B are kg⋅m²⋅s⁻²⋅K⁻¹, which matches the units of the Boltzmann constant (J/K).
Formula for F: Units of (e_c × R): (A⋅s) * (kg⋅m²⋅s⁻²⋅K⁻¹⋅mol⁻¹) = kg⋅m²⋅s⁻¹⋅K⁻¹⋅mol⁻¹⋅A Units of (e_c × R) / k_B: (kg⋅m²⋅s⁻¹⋅K⁻¹⋅mol⁻¹⋅A) / (kg⋅m²⋅s⁻²⋅K⁻¹) = A⋅s⋅mol⁻¹ Result: The units of the calculated value for F are A⋅s⋅mol⁻¹, which match the units of the Faraday constant (C/mol).
Formula for e_c: Units of (k_B × F): (kg⋅m²⋅s⁻²⋅K⁻¹) * (A⋅s⋅mol⁻¹) = kg⋅m²⋅s⁻¹⋅K⁻¹⋅mol⁻¹⋅A Units of (k_B × F) / R: (kg⋅m²⋅s⁻¹⋅K⁻¹⋅mol⁻¹⋅A) / (kg⋅m²⋅s⁻²⋅K⁻¹⋅mol⁻¹) = A⋅s Result: The units of the calculated value for e_c are A⋅s, which match the units of the elementary charge (C).
Formula for R: Units of (k_B × F): (kg⋅m²⋅s⁻²⋅K⁻¹) * (A⋅s⋅mol⁻¹) = kg⋅m²⋅s⁻¹⋅K⁻¹⋅mol⁻¹⋅A Units of (k_B × F) / e_c: (kg⋅m²⋅s⁻¹⋅K⁻¹⋅mol⁻¹⋅A) / (A⋅s) = kg⋅m²⋅s⁻²⋅K⁻¹⋅mol⁻¹ Result: The units of the calculated value for R are kg⋅m²⋅s⁻²⋅K⁻¹⋅mol⁻¹, which match the units of the ideal gas constant (J/(mol⋅K)).
Dimensional Consistency: The dimensional analysis confirms that all four derived formulas are dimensionally consistent. The units on both sides of each equation match, which reinforces the validity of the relationships. Units are Fundamental: The results also indicate the fundamental connections between the units we have used. They confirm that all of the base units used to derive each constant are consistent with the other constants, when the derived formulas are used. import numpy as np
from scipy import constants
# Define the known constants
k_B = 1.380649e-23 # Boltzmann constant (J/K)
F = 96485.33212 # Faraday constant (C/mol)
e_c = 1.602176634e-19 # Elementary charge (C)
R = 8.314462618 # Gas constant J/(mol K)
# Define a function to calculate each constant
def calculate_constants(k_B, F, e_c, R):
"""
Calculates each constant in terms of the other three.
"""
k_B_calc = (e_c * R) / F
F_calc = (e_c * R) / k_B
e_c_calc = (k_B * F) / R
R_calc = (k_B * F) / e_c
return k_B_calc, F_calc, e_c_calc, R_calc
# Calculate the constants
k_B_calc, F_calc, e_c_calc, R_calc = calculate_constants(k_B, F, e_c, R)
# Print the results and check against known values
print("Calculated Constants vs. Known Values:\n")
print(f"Boltzmann constant (k_B)= (e_c * R) / F")
print(f" Calculated: {k_B_calc:.15e} J/K")
print(f" Actual: {k_B:.15e} J/K")
print(f" Difference: {np.abs(k_B_calc-k_B):.3e}\n")
print(f"Faraday constant (F)=(e_c * R) / k_B")
print(f" Calculated: {F_calc:.15e} C/mol")
print(f" Actual: {F:.15e} C/mol")
print(f" Difference: {np.abs(F_calc - F):.3e}\n")
print(f"Elementary charge (e_c)= (k_B * F) / R")
print(f" Calculated: {e_c_calc:.15e} C")
print(f" Actual: {e_c:.15e} C")
print(f" Difference: {np.abs(e_c_calc - e_c):.3e}\n")
print(f"Gas constant (R)=(k_B * F) / e_c")
print(f" Calculated: {R_calc:.15e} J/(mol⋅K)")
print(f" Actual: {R:.15e} J/(mol⋅K)")
print(f" Difference: {np.abs(R_calc-R):.3e}\n")
Solving for the formulasit was not recursive, it actually reached a definition
k_B = R / N_A F = N_A * e_c R = N_A * k_B e_c = 1.602176634 × 10^-19 C All but one has N_A in it. So k_B_calc = (e_c * R) / F k_B = ( 1.602176634 × 10^-19 * N_A * k_B) / N_A * 1.602176634 × 10^-19 C k_B = k_B F_calc = (e_c * R) / k_B F_calc = (1.602176634 × 10^-19 * N_A * k_B) /R / N_A F_calc = (1.602176634 × 10^-19 * N_A * k_B) /N_A * k_B / N_A F_calc = (1.602176634 × 10^-19 * N_A ) At this step I had to note that this is the definition for F F_calc = F e_c_calc = (k_B * F) / R e_c_calc = (R / N_A* N_A * e_c) / N_A * k_B e_c_calc = (R * e_c) / N_A * k_B e_c_calc = (N_A * k_B * e_c) / N_A * k_B e_c_calc = 1.602176634 × 10^-19 R_calc = (k_B * F) / e_c R_calc = (R / N_A* N_A * e_c) / 1.602176634 × 10^-19 R_calc = (R / N_A* N_A * 1.602176634 × 10^-19) / 1.602176634 × 10^-19 R_calc = R
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