Molar Concentration Converter
Convert mol/L (M), mmol/L (mM), µmol/L (µM), mol/m³, lbmol/ft³ for molarity.
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Base Unit
Relative Value
*Diagram shows values relative to the selected base unit (Moles/liter).
Unit Information
What is Moles per liter (mol/L or M)?
Moles per liter (mol/L), often denoted as M (molar), is the standard SI unit for molar concentration. It represents the number of moles of a solute dissolved in one liter of solution. For example, a 1 M solution of sodium chloride (NaCl) contains one mole of NaCl (approximately 58.44 grams) dissolved in enough water to make one liter of solution.
What is Millimoles per liter (mmol/L or mM)?
Millimoles per liter (mmol/L), often denoted as mM (millimolar), is a unit of molar concentration equal to one-thousandth of a mole per liter (1 M = 1000 mM). This unit is commonly used for expressing lower concentrations, such as those found in biological fluids (e.g., blood glucose in mmol/L) or in pharmacological studies.
What are Micromoles per liter (µmol/L or µM)?
Micromoles per liter (µmol/L), denoted as µM (micromolar), is one-millionth of a mole per liter. It's used for even lower concentrations, typical in biochemistry for enzyme kinetics and cellular signaling pathways.
What are Nanomoles per liter (nmol/L or nM)?
Nanomoles per liter (nmol/L), denoted as nM (nanomolar), is one-billionth of a mole per liter. This unit is used for very dilute solutions, such as measuring hormone levels or drug concentrations in blood plasma.
What are Picomoles per liter (pmol/L or pM)?
Picomoles per liter (pmol/L), denoted as pM (picomolar), is one-trillionth of a mole per liter. It's an extremely small unit of concentration used in fields like molecular biology to describe the affinity of proteins and ligands.
What are Moles per cubic meter (mol/m³)?
Moles per cubic meter is an SI unit of molar concentration. Since 1 cubic meter equals 1000 liters, 1 mol/L is equal to 1000 mol/m³. This unit is sometimes used in physics and chemical engineering for large-scale calculations.
What are Pound-moles per cubic foot (lbmol/ft³)?
Pound-moles per cubic foot is an imperial/US customary unit used in some chemical engineering contexts. A pound-mole (lbmol) is the amount of a substance whose mass in pounds is equal to its molar mass. It's used to maintain consistency when working with other imperial engineering units.
Formulas
Molarity (M) = Moles of Solute / Liters of Solution
The fundamental definition of molarity.
1 M = 1000 mM = 1,000,000 µM
Shows the relationship between molar, millimolar, and micromolar.
1 mol/L = 1000 mol/m³
One mole per liter is equivalent to 1000 moles per cubic meter.
C₁V₁ = C₂V₂
The dilution equation, used to calculate the volume (V₁) of a stock solution of concentration (C₁) needed to prepare a solution of a desired new volume (V₂) and concentration (C₂).
Key Reference Points
- Concentration of NaCl in seawater: ~0.5-0.6 M.
- Physiological saline solution (0.9% NaCl): ~0.154 M or 154 mM.
- Blood glucose (normal fasting): ~3.9-5.5 mmol/L (mM).
- Concentrated hydrochloric acid (HCl): ~12 M.
- Concentration of Ca²⁺ ions inside a typical cell: ~100 nM.
- 1 Molar (1M) solution is a standard laboratory concentration.
- pH 7 indicates a hydrogen ion (H⁺) concentration of 10⁻⁷ M (or 100 nM).
- High-affinity antibody-antigen binding can occur at picomolar (pM) concentrations.
- Typical enzyme concentrations in cells are in the micromolar (µM) range.
- Concentration of pure water is ~55.5 M.
Did You Know?
The concept of a 'mole' is central to molar concentration. One mole of any substance contains Avogadro's number of entities (atoms, molecules, ions, etc.), which is approximately 6.022 × 10²³. This constant allows chemists to relate macroscopic measurements (like grams) to the microscopic world of atoms and molecules.
Osmolarity is a measure of the total concentration of all solute particles in a solution, often expressed in osmoles per liter (Osm/L) or milliosmoles per liter (mOsm/L). It's particularly important in biology and medicine for understanding fluid balance across cell membranes.
To prepare a solution of a specific molarity, chemists use volumetric flasks, which are calibrated to contain a precise volume at a specific temperature. This ensures accuracy in the final concentration.
The pH scale, which measures acidity, is a logarithmic scale of the molar concentration of hydrogen ions (H+). A change of one pH unit represents a tenfold change in H+ concentration.
For very dilute solutions, concentrations are sometimes expressed in parts per million (ppm) or parts per billion (ppb). These can be converted to molarity if the molar mass of the solute and the density of the solution are known.
Titration is a common laboratory method used to determine the unknown concentration of a solution by reacting it with a solution of known concentration. The endpoint of the reaction allows for the calculation of the unknown molarity.
Ionic strength is a measure of the concentration of ions in a solution. It's calculated based on the molar concentrations and charges of all ions present and is important in understanding electrochemical and biochemical interactions.
The Dead Sea is one of the saltiest bodies of water on Earth. Its salt concentration is extremely high, around 34.2% by mass, which corresponds to a very high molar concentration of various salts, making it much denser than freshwater.
The concentration of water in pure water itself is surprisingly high. It can be calculated to be approximately 55.5 M (moles per liter).
This law relates the attenuation of light through a substance to its concentration. Spectrophotometry uses this principle to measure the molar concentration of a solute by analyzing how much light it absorbs.
Normality is an older unit of concentration that is equal to the molarity multiplied by an equivalence factor. It was used in acid-base chemistry to simplify titration calculations but is less common today.
The pound-mole (lbmol) is an analogue to the gram-mole used in some US engineering contexts. It is the amount of a substance whose mass in pounds is numerically equal to its molar mass. 1 lbmol is about 453.6 g-mol.
In chemical kinetics, the rate of a reaction is often dependent on the molar concentration of the reactants raised to some power. Understanding concentration is key to controlling reaction speeds.
In laboratories, chemists often prepare concentrated 'stock solutions' of a known molarity. They can then easily create more dilute solutions for experiments by taking a specific volume of the stock solution and diluting it with a solvent.
For substances that do not exist as molecules in solution (like ionic compounds), the term 'formality' (F) was sometimes used instead of molarity. It represents moles of formula units per liter of solution. Today, molarity is used for all such cases.
Colligative properties, like boiling point elevation and freezing point depression, depend on the concentration of solute particles. Molality (moles/kg solvent) is often preferred for these calculations because it's independent of temperature changes, unlike molarity.
In biochemistry, the Michaelis-Menten constant (Km) is a measure of the concentration of substrate at which an enzyme reaction rate is at half its maximum. It has units of molar concentration and is crucial for understanding enzyme efficiency.
The Ksp is an equilibrium constant for a solid substance dissolving in an aqueous solution. It's calculated using the molar concentrations of the ions in a saturated solution and indicates how soluble the substance is.