chemlib¶

Chemlib is a pure Python library that supports a variety of functions pertaining to the vast field of chemistry. It is under active development and continually improved to include more and more features.

Installation¶

Use the Python Package Installer (PyPI):

$ pip install -U chemlib

Contents¶

Core Data¶

Periodic Table¶

class chemlib.chemistry.PeriodicTable(*args: Any, **kwargs: Any)¶: Bases:

Column Names

>>> list(chemlib.pte)   #Column names
['AtomicNumber', 'Element', 'Symbol', 'AtomicMass', 'Neutrons', 'Protons', 'Electrons', 'Period', 'Group', 'Phase', 'Radioactive', 'Natural', 'Metal', 'Nonmetal', 'Metalloid', 'Type', 'AtomicRadius', 'Electronegativity', 'FirstIonization', 'Density', 'MeltingPoint', 'BoilingPoint', 'Isotopes', 'Discoverer', 'Year', 'SpecificHeat', 'Shells', 'Valence', 'Config', 'MassNumber']

Elements¶

class chemlib.chemistry.Element(*args: Any, **kwargs: Any)¶

Contains all the properties of the respective element:

>>> from chemlib import Element
>>> xenon = Element('Xe') #Instantiate with symbol of Element
>>> xenon.properties
{'AtomicNumber': 54.0, 'Element': 'Xenon', 'Symbol': 'Xe', 'AtomicMass': 131.293, 'Neutrons': 77.0, 'Protons': 54.0, 'Electrons': 54.0, 'Period': 5.0, 'Group': 18.0, 'Phase': 'gas', 'Radioactive': False, 'Natural': True, 'Metal': False, 'Nonmetal': True, 'Metalloid': False, 'Type': 'Noble Gas', 'AtomicRadius': '1.2', 'Electronegativity': nan, 'FirstIonization': '12.1298', 'Density': '0.00589', 'MeltingPoint': '161.45', 'BoilingPoint': '165.03', 'Isotopes': 31.0, 'Discoverer': 'Ramsay and Travers', 'Year': '1898', 'SpecificHeat': '0.158', 'Shells': 5.0, 'Valence': 8.0, 'Config': '[Kr] 4d10 5s2 5p6', 'MassNumber': 131.0}
>>> xenon.AtomicMass
131.293
>>> xenon.FirstIonization
'12.1298'

chemlib.chemistry.Element.AtomicNumber: float¶

chemlib.chemistry.Element.Element: str = The name of the element¶

chemlib.chemistry.Element.Symbol: str = The symbol of the element¶

chemlib.chemistry.Element.AtomicMass: float¶

chemlib.chemistry.Element.Neutrons: float¶

chemlib.chemistry.Element.Protons: float¶

chemlib.chemistry.Element.Electrons: float¶

chemlib.chemistry.Element.Period: float¶

chemlib.chemistry.Element.Group: float¶

chemlib.chemistry.Element.Phase: str = The state of matter of the element at room temperature.¶

chemlib.chemistry.Element.Radioactive: boolean¶

chemlib.chemistry.Element.Natural: boolean¶

chemlib.chemistry.Element.Metal: boolean¶

chemlib.chemistry.Element.Nonmetal: boolean¶

chemlib.chemistry.Element.Metalloid: boolean¶

chemlib.chemistry.Element.Type: str¶

chemlib.chemistry.Element.AtomicRadius: str¶

chemlib.chemistry.Element.Electronegativity: str or NaN¶

chemlib.chemistry.Element.FirstIonization: str or NaN¶

chemlib.chemistry.Element.Density: float = The density in kg/L¶

chemlib.chemistry.Element.MeltingPoint: float¶

chemlib.chemistry.Element.BoilingPoint: float¶

chemlib.chemistry.Element.Isotopes: float¶

chemlib.chemistry.Element.Discoverer: str¶

chemlib.chemistry.Element.Year: str = Year of discovery¶

chemlib.chemistry.Element.SpecificHeat: float¶

chemlib.chemistry.Element.Shells: float¶

chemlib.chemistry.Element.Valence: float¶

chemlib.chemistry.Element.Config: float = Electron configuration¶

chemlib.chemistry.Element.MassNumber: float¶

Other Constants¶

chemlib.AVOGADROS_NUMBER: float = 6.02e+23¶

Contains Avogaadro’s Number, which relates the number of constituent particles in a sample with the amount of substance in that sample.

>>> import chemlib
>>> chemlib.AVOGADROS_NUMBER
6.02e+23

chemlib.c: float = 2.998e+8¶

The speed of light.

chemlib.h: float = 6.626e-34¶

Planck’s constant.

chemlib.R: float = 1.0974e+7¶

Rydberg constant.

Chemical Compounds¶

Making a Compound¶

class chemlib.chemistry.Compound(*args: Any, **kwargs: Any)¶

Instantiate a chemlib.Compound object with the formula of the compound.

>>> from chemlib import Compound
>>> water = Compound("H2O")
>>> water.formula
'H₂O₁'

chemlib.chemistry.Compound.occurences: dict¶

A dictionary containing the frequencies of the constituent elements in the compound.
>>> water.occurences
{'H': 2, 'O': 1}

Molar Mass¶

chemlib.chemistry.Compound.molar_mass(self)¶

Returns: The molar mass in (g/mol) of the compound
Return type: float

>>> water.molar_mass()
18.01

Percentage Composition by Mass¶

chemlib.chemistry.Compound.percentage_by_mass(self, element)¶

Get the percentage composition by mass of a certain element of the compound.

Parameters: element (str) – The constituent element of which the user wants to get percentage composition.
Returns: The percentage composition by mass of the element in the compound.
Return type: float

>>> water.percentage_by_mass('H') #Percent of Hydrogen in Compound
11.183
>>> water.percentage_by_mass('O') #Percent of Oxygen in Compound
88.834

Stoichiometry¶

chemlib.chemistry.Compound.get_amounts(self, **kwargs)¶

Get stoichiometric amounts of the compound given one measurement.

Parameters

compound_number (int) – The chosen compound in the reaction by order of appearance.
kwargs – The amount of the chosen compound (grams=, moles=, or molecules=)

Returns

The gram, mole, and molecule amounts of the compound.

Return type

dict

Raises

ValueError – If the kwargs argument isn’t either grams, moles, or molecules
ValueError – if more than one argument is given under kwargs

Get the amount of moles and molecules of water given 2 grams of water.

>>> water.get_amounts(grams = 2)
{'Compound': 'H₂O₁', 'Grams': 2, 'Moles': 0.111, 'Molecules': 6.685e+22}

Get the amount of grams and molecules of water given 2 moles of water.

>>> water.get_amounts(moles = 2)
{'Compound': 'H₂O₁', 'Grams': 36.02, 'Moles': 2, 'Molecules': 1.204e+24}

Get the amount of moles and grams of water given 2e+24 molecules of water.

>>> water.get_amounts(molecules = 2e+24)
{'Compound': 'H₂O₁', 'Grams': 59.834, 'Moles': 3.3223, 'Molecules': 2e+24}

Empirical Formulae¶

EF by Percentage Composition¶

chemlib.chemistry.empirical_formula_by_percent_comp(**kwargs)¶

Get the empirical formula given the percentage compositions of all elements in the compound.

Parameters: kwargs – The percentage compositions of elements in the compound (<Element symbol> = <Percentage Composition> ...)
Returns: The empirical formula of the compound.
Return type: chemlib.chemistry.Compound
Raises: ValueError – If the sums of the percentages is not equal to 100.

Get the empirical formula of a compound that is composed of 80.6% C, and 19.4% H by mass:

>>> from chemlib import empirical_formula_by_percent_comp as efbpc
>>> efbpc(C = 80.6, H = 19.4)
'C1H3'

Combustion Analysis¶

chemlib.chemistry.combustion_analysis(CO2, H2O)¶

Get the empirical formula of a hydrocarbon given the grams of CO2 and grams of H2O formed from its combustion.

Parameters

CO2 – The grams of carbon dioxide formed as a result of the combustion of the hydrocarbon.
H2O – The grams of water formed as a result of the combustion of the hydrocarbon.

Returns

The empirical formula of the hydrocarbon.

Return type

str

A hydrocarbon fuel is fully combusted with 18.214 g of oxygen to yield 23.118 g of carbon dioxide and 4.729 g of water. Find the empirical formula for the hydrocarbon.

>>> from chemlib.chemistry import combustion_analysis
>>> combustion_analysis(23.118, 4.729)
'CH'

Chemical Reactions¶

Making a Reaction¶

class chemlib.chemistry.Reaction(*args: Any, **kwargs: Any)¶

Instantiate a chemlib.Reaction object with a list of reactant Compounds and product Compounds.

>>> from chemlib import Compound, Reaction
>>> N2O5 = Compound("N2O5")
>>> H2O = Compound("H2O")
>>> HNO3 = Compound("HNO3")
>>> r = Reaction([N2O5, H2O], [HNO3])

classmethod chemlib.chemistry.Reaction.by_formula(cls, formula: str)¶

OR Instantiate a chemlib.Reaction object using a string to represent the formula:

In the formula string, place the formulae of reactants separated by + signs on the left side of the arrow -->. On the right side of the arrow, place the formulae of products separated by + signs:

>>> from chemlib import Reaction
>>> r = Reaction.by_formula("N2O5 + H2O --> HNO3")

chemlib.chemistry.Reaction.formula: str¶
>>> r.formula
'1N₂O₅ + 1H₂O₁ --> 1H₁N₁O₃'
chemlib.chemistry.Reaction.is_balanced: boolean¶
>>> r.is_balanced
False
chemlib.chemistry.Reaction.reactant_formulas: list¶
>>> r.reactant_formulas
['N₂O₅', 'H₂O₁']
chemlib.chemistry.Reaction.product_formulas: list¶
>>> r.product_formulas
['H₁N₁O₃']

Combustion Reactions¶

class chemlib.chemistry.Combustion(compound)¶

Inherits from chemlib.chemistry.Reaction

Makes a chemical reaction involving the combustion of one compound. Formula will be balanced.

>>> from chemlib import Compound, Combustion
>>> methane = Compound('CH4')
>>> c = Combustion(methane)
>>> c.formula
'1C₁H₄ + 2O₂ --> 2H₂O₁ + 1C₁O₂'
>>> c.is_balanced
True

Balancing the Equation¶

chemlib.chemistry.Reaction.balance(self) → None¶

Balances the chemical equation using linear algebra. See Applications of Linear Algebra in Chemistry.

>>> r.balance()
>>> r.formula
'1N₂O₅ + 1H₂O₁ --> 2H₁N₁O₃'
>>> r.is_balanced
True

Stoichiometry¶

chemlib.chemistry.Reaction.get_amounts(self, compound_number, **kwargs)¶

Get stoichiometric amounts of ALL compounds in the reaction given the amount of one compound.

Parameters

compound_number (int) – The chosen compound in the reaction by order of appearance.
kwargs – The amount of the chosen compound (grams=, moles=, or molecules=)

Returns

the amounts of each compound in the reaction

Return type

list of dicts

Raises

ValueError – if the compound_number is less than 1 or greater than the number of compounds in the reaction
ValueError – if more than one argument is given under kwargs

Best demonstrated by example:

>>> r.formula
'1N₂O₅ + 1H₂O₁ --> 2H₁N₁O₃'

Get the amounts of ALL compounds in the above reaction given 5 grams of N₂O₅. It is the first compound in the reaction by order of appearance (left to right).

>>> r.get_amounts(1, grams=5)
[{'Compound': 'N₂O₅', 'Grams': 5, 'Moles': 0.0463, 'Molecules': 2.787e+22}, {'Compound': 'H₂O₁', 'Grams': 0.834, 'Moles': 0.0463, 'Molecules': 2.787e+22}, {'Compound': 'H₁N₁O₃', 'Grams': 5.835, 'Moles': 0.0926, 'Molecules': 5.575e+22}]

Get the amounts of ALL compounds in the above reaction given 3.5 moles of HNO₃. It is the third compound in the reaction by order of appearance (left to right).

>>> r.get_amounts(3, moles=3.5)
[{'Compound': 'N₂O₅', 'Grams': 189.018, 'Moles': 1.75, 'Molecules': 1.054e+24}, {'Compound': 'H₂O₁', 'Grams': 31.518, 'Moles': 1.75, 'Molecules': 1.054e+24}, {'Compound': 'H₁N₁O₃', 'Grams': 220.535, 'Moles': 3.5, 'Molecules': 2.107e+24}]

Limiting Reagent¶

chemlib.chemistry.Reaction.limiting_reagent(self, *args, mode='grams')¶

Get the limiting reagent (limiting reactant) in the chemical reaction.

Parameters

args – The amounts of each reactant to use in the chemical reaction.
mode (str) – The units of each amount in args. Default is grams, can also be moles or molecules.

Returns

The limiting reagent of the reaction.

Return type

chemlib.chemistry.Compound

Raises

TypeError – If the number of args doesn’t match the number of reactants in the reaction.
ValueError – If the mode is not grams, moles, or molecules.

Find the limiting reagent of the reaction when using 50 grams of the first reactant (N₂O₅) and 80 grams of the second reactant (H₂O):

>>> lr = r.limiting_reagent(50, 80)
>>> lr.formula
'N₂O₅'

Find the limiting reagent of the reaction when using 3 moles of the first reactant (N₂O₅) and 1 mole of the second reactant (H₂O):

>>> lr = r.limiting_reagent(3, 1, mode = 'moles')
>>> lr.formula
'H₂O₁'

Aqueous Solutions¶

Acidity Calculation (pH, pOH)¶

chemlib.chemistry.pH(**kwargs)¶

For any inputted pH, pOH, [H+], or [OH-], finds the corresponding values.

Parameters: kwargs – The value of the chosen input (pH=, pOH=, H=, or OH=)
Return type: dict

What is the pH, pOH and [OH-] given a [H+] of 1.07x10^-6 M?

>>> import chemlib
>>> chemlib.pH(H=1.07e-6)
{'H': 1.07e-06, 'pOH': 8.029, 'pH': 5.971, 'OH': 9.354e-09, 'acidity': 'acidic'}

What is the pH, pOH, and [H+] given a [OH-] of 2.06x10^-3 M?

>>> chemlib.pH(OH=2.06e-3)
{'OH': 0.002, 'H': 5e-12, 'pOH': 2.699, 'pH': 11.301, 'acidity': 'basic'}

What is the pOH, [H+], and [OH-] given a pH of 5.2?

>>> chemlib.pH(pH = 5.2)
{'pH': 5.2, 'OH': 1.585e-09, 'H': 6.309e-06, 'pOH': 8.8, 'acidity': 'acidic'}

Making a Solution¶

class chemlib.chemistry.Solution(self, solute, molarity)¶

Instantiate a chemlib.Solution object with the formula of the solute, and the molarity in mol/L.

param solute (str)

The formula of the solute without using subscripts OR a chemlib.chemistry.Compound object.

param molarity (float)

How many moles of solute per liter of solution

>>> from chemlib import Solution
>>> Solution('AgCl', 2)
<chemlib.chemistry.Solution object at 0x03F46370>
>>> s = Solution('AgCl', 2)
>>> s.molarity
2

classmethod chemlib.chemistry.Solution.by_grams_per_liters(cls, solute, grams, liters)¶

OR you can make a Solution with the solute, and grams per liter.

param str solute

The formula of the solute without using subscripts OR a chemlib.chemistry.Compound object.

param float grams

How many grams of solute

param float liters

How many liters of solution

>>> from chemlib import Solution
>>> s = Solution.by_grams_per_liters("NaCl", 10, 1)
>>> s.molarity
0.1711

Dilutions¶

chemlib.chemistry.Solution.dilute(self, V1=None, M2=None, V2=None, inplace=False) → dict¶

Using formula M1*V1 = M2*V2

param float V1

The starting volume of the solution. [Must be specified]

param float M2

The ending molarity after dilution.

param float V2

The ending volume after dilution

param bool inplace

You can set to true if the old molarity is to be replaced by the new molarity

return

The new volume and the new molarity.

rtype

dict

raises TypeError

if a starting volume is not specified

raises TypeError

if both M2 and V2 are specified

To find the dilution of 2.5 L of 0.25M NaCl to a 0.125M NaCl solution:

>>> from chemlib import Solution
>>> s = Solution("NaCl", 0.25)
>>> s.dilute(V1 = 2.5, M2 = 0.125)
{'Solute': 'Na₁Cl₁', 'Molarity': 0.125, 'Volume': 5.0}

Electrochemistry¶

Galvanic (Voltaic) Cells¶

class chemlib.electrochemistry.Galvanic_Cell(self, electrode1: str, electrode2: str)¶

Parameters

(str) (electrode2) – The elemental composition of one of the electrodes of the galvanic cell.
(str) – The elemental composition of the other electrode of the galvanic cell.

Raises

NotImplementedError – If either of the electrodes is invalid or its reduction potential is unknown.

Make a Galvanic Cell with Lead and Zinc electrodes:

>>> from chemlib import Galvanic_Cell
>>> g = Galvanic_Cell("Pb", "Zn")
>>>

chemlib.electrochemistry.Galvanic_Cell.properties: dict¶

A dictionary of the cell’s properties:

>>> g.properties
{'Cell': 'Zn | Zn2+ || Pb2+ | Pb', 'Anode': 'Zn', 'Cathode': 'Pb', 'Cell Potential': 0.63}
>>>

chemlib.electrochemistry.Galvanic_Cell.cell_potential: float¶

Access the cell potential of the galvanic cell:

>>> g.cell_potential
0.63
>>> g.E0
0.63

chemlib.electrochemistry.Galvanic_Cell.diagram: PIL.Image¶

The diagram of the galvanic cell is a PIL.Image object. To generate diagram:

>>> g.draw()

To save (as png file):

>>> g.diagram.save("filename.png")
>>>

Electrolysis¶

chemlib.electrochemistry.electrolysis(element: str, n: int, **kwargs) → dict:¶

Parameters

(str) (element) – The symbol of a chemical element.
(int) (n) – The moles of electrons transferred.
kwargs – Provide two of the values from amps, seconds, and grams.

Raises

TypeError – If not only 2 of the parameters in kwargs are specified.

Example: Copper metal is purified by electrolysis. How much copper metal (in grams) could be produced from copper (ii) oxide by applying a current of 10.0 amps at the appropriate negative potential for 12.0 hours?

>>> from chemlib import electrolysis
>>> electrolysis('Cu', 2, amps = 10, seconds=12*60*60)
{'element': 'Cu', 'n': 2, 'seconds': 43200, 'amps': 10, 'grams': 142.25979167746283}
>>>

Example: How long would it take to electroplate a flute with 28.3 g of silver at a constant current of 2.0 amps using AgNO3?

>>> from chemlib import electrolysis
>>> electrolysis("Ag", 2, amps = 2, grams = 28.3)
{'element': 'Ag', 'n': 2, 'seconds': 25313.582341380206, 'amps': 2, 'grams': 28.3}
>>>

Example: How much current was used to produce 805 grams of Aluminum metal from Al2O3 in 24 hours?

>>> from chemlib import electrolysis
>>> electrolysis("Al", 3, grams = 805, seconds = 24*60*60)
{'element': 'Al', 'n': 3, 'seconds': 86400, 'amps': 99.95144010616133, 'grams': 805}
>>>

Quantum Mechanics¶

Electromagnetic Waves¶

class chemlib.quantum_mechanics.Wave(**kwargs)¶

Makes a Wave object given either wavelength (in meters), frequency (in Hz), or energy (in J per photon), and calculates the aforementioned values.

param kwargs: The value of the known variable (wavelength=, frequency=, or energy=)

Determine the wavelength, frequency, and energy of a wave with frequency 2e+17 Hz:

>>> from chemlib import Wave
>>> w = Wave(frequency=2e+17)
>>> w.properties
{'wavelength': 1.499e-09, 'frequency': 2e+17, 'energy': 1.325e-16}

Determine the wavelength, frequency, and energy of a wave with wavelength 3e-9 m:

>>> w = Wave(wavelength=3e-9)
>>> w.properties
{'wavelength': 3e-09, 'frequency': 9.993e+16, 'energy': 6.622e-17}

Determine the wavelength, frequency, and energy of a wave with energy 3e-15 Joules per particle:

>>> from chemlib import Wave
>>> w = Wave(energy=3e-15)
>>> w.properties
{'wavelength': 4.387e-44, 'frequency': 4.528e+18, 'energy': 3e-15}

chemlib.quantum_mechanics.Wave.properties: dict¶

chemlib.quantum_mechanics.Wave.wavelength: float¶

chemlib.quantum_mechanics.Wave.frequency: float¶

chemlib.quantum_mechanics.Wave.energy: float¶

Electrons and Orbitals¶

chemlib.quantum_mechanics.energy_of_hydrogen_orbital(n) → float¶

Gets the energy of an electron in the nth orbital of the Hydrogen atom in Joules.

>>> from chemlib import energy_of_hydrogen_orbital
>>> energy_of_hydrogen_orbital(3)
-2.4221749394666667e-19

chemlib¶

Installation¶

Contents¶

Core Data¶

Periodic Table¶

Elements¶

Other Constants¶

Chemical Compounds¶

Making a Compound¶

Molar Mass¶

Percentage Composition by Mass¶

Stoichiometry¶

Empirical Formulae¶

EF by Percentage Composition¶

Combustion Analysis¶

Chemical Reactions¶

Making a Reaction¶

Combustion Reactions¶

Balancing the Equation¶

Stoichiometry¶

Limiting Reagent¶

Aqueous Solutions¶

Acidity Calculation (pH, pOH)¶

Making a Solution¶

Dilutions¶

Electrochemistry¶

Galvanic (Voltaic) Cells¶

Electrolysis¶

Quantum Mechanics¶

Electromagnetic Waves¶

Electrons and Orbitals¶

Indices and tables¶