Flow - Molar Converter
Convert molar flow rate, the amount of substance moving per unit of time, between mol/s, mol/min, mol/h, mmol/h, kmol/h and prefixed mole-per-second units. Pick two units, enter a value and read the result instantly.
Select two units to see the conversion factor.
Molar flow counts moles per time. Converting it to grams per time needs the molar mass, and converting it to liters per time needs the density or gas conditions, so this tool does not do either.
Molar Flow Formula
Every molar flow unit is an amount of substance (mole, millimole, kilomole or an SI-prefixed mole) divided by a time unit, so each one is a fixed multiple of one reference unit, the mole per second (mol/s). To convert, multiply the value by the size of the source unit in mol/s, then divide by the size of the target unit in mol/s. The SI prefixes are exact powers of ten and the time bases are 60 s, 3,600 s and 86,400 s.
What Is Molar Flow Rate?
Molar flow rate is the amount of substance that passes a point in a unit of time. The amount of substance is counted in moles, where one mole contains exactly 6.02214076 × 10²³ elementary entities (atoms, molecules or ions). The SI unit of molar flow is the mole per second (mol/s), and chemical engineers often write it as ṅ.
Molar flow is the natural quantity for chemical reactions, because reactions combine molecules in fixed ratios. If a reactor consumes 2 mol/s of one reactant for every 1 mol/s of another, the molar flows show the balance directly, whatever the temperature, pressure or volume of the streams. This is why reactor design, gas absorption and distillation calculations are written in molar flows.
Molar flow is different from mass flow (kilograms per time) and volumetric flow (liters or cubic meters per time). Mass flow equals molar flow multiplied by the molar mass of the substance. Volumetric flow of a gas additionally depends on its pressure and temperature, since for an ideal gas ṅ = P × Q ÷ (R × T).
Supported Units
This converter supports the following 26 molar flow units: moles per second with every SI prefix from exa to atto, and moles, millimoles and kilomoles per minute, hour and day. The last column shows how many moles per second one unit equals.
| Unit | Symbol | Value in mol/s |
|---|---|---|
| Mole per second | mol/s | 1 |
| Examole per second | Emol/s | 1e+18 |
| Petamole per second | Pmol/s | 1e+15 |
| Teramole per second | Tmol/s | 1e+12 |
| Gigamole per second | Gmol/s | 1,000,000,000 |
| Megamole per second | Mmol/s | 1,000,000 |
| Kilomole per second | kmol/s | 1,000 |
| Hectomole per second | hmol/s | 100 |
| Dekamole per second | damol/s | 10 |
| Decimole per second | dmol/s | 0.1 |
| Centimole per second | cmol/s | 0.01 |
| Millimole per second | mmol/s | 0.001 |
| Micromole per second | µmol/s | 1e-6 |
| Nanomole per second | nmol/s | 1e-9 |
| Picomole per second | pmol/s | 1e-12 |
| Femtomole per second | fmol/s | 1e-15 |
| Attomole per second | amol/s | 1e-18 |
| Mole per minute | mol/min | 0.01666666667 |
| Mole per hour | mol/h | 0.0002777777778 |
| Mole per day | mol/d | 1.157407407e-5 |
| Millimole per minute | mmol/min | 1.666666667e-5 |
| Millimole per hour | mmol/h | 2.777777778e-7 |
| Millimole per day | mmol/d | 1.157407407e-8 |
| Kilomole per minute | kmol/min | 16.66666667 |
| Kilomole per hour | kmol/h | 0.2777777778 |
| Kilomole per day | kmol/d | 0.01157407407 |
How to Use the Flow - Molar Converter
- Type the molar flow rate in the value box. Decimals and scientific notation such as 0.0025 or 2.5e-3 are accepted.
- Choose the From unit and the To unit.
- The result appears instantly, or press Convert Now. Very large or very small results are shown in scientific notation.
- Use Swap Units to reverse the conversion, Copy Result to copy the answer, open Show this value in all units for a full list, and Clear to start again.
Step-by-step by hand
- Find the size of each unit in the common base unit (mol/s): 1 mol/min = 0.01666666667 mol/s and 1 mol/s = 1 mol/s.
- Divide the source size by the target size to get the conversion factor: 0.01666666667 ÷ 1 = 0.01666666667, so 1 mol/min = 0.01666666667 mol/s.
- Multiply by your value: 120 mol/min × 0.01666666667 = 2 mol/s.
Molar flow cannot be negative, so only zero and positive numbers are accepted.
Common Molar Flow Conversions
- Reactor feed: 120 mol/min equals 2 mol/s or 7,200 mol/h.
- Industrial plant: 5 kmol/h equals 1.388888889 mol/s, which is 83.33333333 mol/min.
- Laboratory dosing: 0.5 mmol/min equals 8.333333333 µmol/s.
- Daily throughput: 24 kmol/day equals 1 kmol/h.
- Very small flows: 3 nmol/s equals 0.003 µmol/s or 0.0108 mmol/h.
- Mass link by hand: water has a molar mass of about 18.015 g/mol, so 2 mol/min is about 36.03 g/min.
Mole per Minute Conversion – Common Values
Quick reference for frequently used values
| Mole/minute | Mole/second | Mole/hour | Millimole/second | Kilomole/hour |
|---|---|---|---|---|
| 0.01 | 0.0001666666667 | 0.6 | 0.1666666667 | 0.0006 |
| 0.1 | 0.001666666667 | 6 | 1.666666667 | 0.006 |
| 1 | 0.01666666667 | 60 | 16.66666667 | 0.06 |
| 5 | 0.08333333333 | 300 | 83.33333333 | 0.3 |
| 10 | 0.1666666667 | 600 | 166.6666667 | 0.6 |
| 30 | 0.5 | 1,800 | 500 | 1.8 |
| 60 | 1 | 3,600 | 1,000 | 3.6 |
| 100 | 1.666666667 | 6,000 | 1,666.666667 | 6 |
| 500 | 8.333333333 | 30,000 | 8,333.333333 | 30 |
| 1,000 | 16.66666667 | 60,000 | 16,666.66667 | 60 |
Where and Why This Conversion Is Used
- Chemical reactor design: feed, product and recycle streams are balanced in mol/s, mol/h or kmol/h.
- Gas processing and combustion: molar flows of fuel and air give the stoichiometry directly.
- Laboratory and pilot plants: syringe pumps and mass-flow controllers are specified in mmol/min or µmol/s.
- Environmental chemistry: emission and deposition fluxes are often written in mol per time.
- Physiology and biochemistry: uptake and production rates are measured in mmol/h, µmol/min or nmol/s.
- Education: mass-balance and chemical-engineering exercises use molar flow as the standard quantity.
To compare with mass or volume per time, see the Flow - Mass Converter and the Flow Converter. Related concentration units are in the Concentration - Molar Converter.