Molar Flow Rate & Stoichiometry Calculator

Chemical Reaction Engineering, Stoichiometry & Molar Flow Metrology

Molar Flow Rate is the number of moles of substance passing through a process cross-section per unit time:

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• Universal Molar Flow Conversion Formulas (IUPAC Standards)**:

n_lbmol/h = n_kmol/h × 2.20462262

n_mol/s = n_kmol/h × 1,0003,600 = n_kmol/h × 0.277778

n_kmol/h = n_lbmol/h2.20462262 = n_lbmol/h × 0.453592

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• Stoichiometric Mass Flow & Ideal Gas Volumetric Flow**:

m_kg/h = n_kmol/h × M_w, kg/kmol

V_STP = n_kmol/h × 22.414

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• Standard Chemical Reaction Benchmarks**:

• Lab Microreactor: 0.036 kmol/h 0.0726 kg/h

• Methane Reformer: 220.46 lbmol/h 1,604 kg/h 2,241 Nm^3/h

• Ammonia Synthesis: 1,102.3 lbmol/h 14,007 kg/h 11,207 Nm^3/h

• CO₂ Flue Gas Capture: 551.16 lbmol/h 11,003 kg/h

How to Use This Calculator

Enter your Molar Flow Rate Magnitude (ṅ) (e.g. 100 in ṅ), From Molar Flow Unit — choose from Kilomoles per Hour (kmol/h - Chemical Engineering), Moles per Second (mol/s - SI Base Unit), Pound-Moles per Hour (lbmol/h - US Engineering), To Molar Flow Unit — choose from Pound-Moles per Hour (lbmol/h), Moles per Second (mol/s), Kilomoles per Hour (kmol/h), Molecular Weight (M_w in g/mol = kg/kmol) (e.g. 16.04 in g/mol), and Chemical Reaction & Process Benchmark — choose from Custom Chemical System, Methane Steam Reforming (100 kmol/h CH₄, Mw=16.04) → 220.46 lbmol/h | 1,604 kg/h (3,536 lb/h) | 2,241 Nm³/h, Ammonia Synthesis Feed (500 kmol/h N₂, Mw=28.01) → 1,102.3 lbmol/h | 14,007 kg/h | 11,207 Nm³/h. Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Conversion factors used in this calculator:

1 lbmol = 453.59237 mol

Worked Example

A chemical process engineer operating a methane reformer with 100.0 kmol/h of CH_4 calculates the stream carries 220.46 lbmol/h and occupies 2,241 Normal cubic meters per hour at standard STP.

Understanding Your Result

Chemical calculations require careful attention to significant figures — your result is only as precise as your least precise input. For laboratory work, verify that temperature, pressure, and concentration conditions match the formula's assumed standard state (typically 25°C and 1 atm). Compare your result against published reference values for the specific compound or reaction. Safety note: laboratory chemical calculations should always be verified by a qualified chemist before practical application.