Chemistry Calculator: Molarity, Dilution, Normality & Molar Mass
Calculate molarity, the mass needed to prepare a solution, dilution (M1·V1 = M2·V2), normality, and how to prepare a solution from concentrated reagents such as 37% HCl or 98% H2SO4. Pick a substance to fill in its molar mass.
Molarity formula
Molarity (M) is moles of solute per litre of solution: M = n / V = mass / (molar mass × V), with mass in grams, molar mass in g/mol and V in litres.
Example: 1 L of 0.1 M NaOH (molar mass 40.00) needs 0.1 × 1 × 40.00 = 4.0 g NaOH, dissolved and made up to 1 L in a volumetric flask.
Dilution formula (M1·V1 = M2·V2)
Diluting keeps the moles of solute constant: M1 × V1 = M2 × V2. Example: 100 mL of 0.1 M HCl from 1 M HCl → V1 = 0.1 × 100 / 1 = 10 mL of 1 M HCl diluted to 100 mL.
Normality formula
Normality (N) = M × equivalents: H⁺ released for acids (HCl 1, H2SO4 2, H3PO4 3), OH⁻ for bases (NaOH 1, Ca(OH)2 2), electrons for redox agents. 0.05 M H2SO4 = 0.1 N.
Preparing a solution from a concentrated reagent
Molarity of a concentrated reagent = (% × density × 10) / molar mass. 37% HCl (ρ 1.19) ≈ 12.1 M, so 1 L of 0.1 M needs ≈ 8.3 mL of 37% HCl. Always add acid to water. The % and density values are typical; use the figures on your reagent's label/CoA.
Molar mass table of common chemicals
| Substance | Formula | Mr (g/mol) |
|---|---|---|
| Ammonia | NH3 | 17.03 |
| Ammonium Chloride | NH4Cl | 53.49 |
| Acetic Acid | CH3COOH | 60.05 |
| Boric Acid | H3BO3 | 61.83 |
| Phosphoric Acid | H3PO4 | 97.99 |
| Hydrochloric Acid | HCl | 36.46 |
| Nitric Acid | HNO3 | 63.01 |
| Oxalic Acid | H2C2O4 | 90.03 |
| Salicylic Acid | C7H6O3 | 138.12 |
| Citric Acid | C6H8O7 | 192.12 |
| Stearic Acid | C18H36O2 | 284.50 |
| Sulfuric Acid | H2SO4 | 98.08 |
| Acetone | C3H6O | 58.08 |
| Aspirin (Acetylsalicylic Acid) | C9H8O4 | 180.16 |
| Barium Chloride | BaCl2 | 208.23 |
| Sulfur | S | 32.07 |
| Benzene | C6H6 | 78.11 |
| Iron(III) Chloride | FeCl3 | 162.20 |
| Dipotassium Hydrogen Phosphate | K2HPO4 | 174.18 |
| Disodium EDTA Dihydrate | Na2EDTA·2H2O | 372.24 |
| Disodium Hydrogen Phosphate | Na2HPO4 | 141.96 |
| EDTA (Ethylenediaminetetraacetic Acid) | C10H16N2O8 | 292.24 |
| Ethanol | C2H5OH | 46.07 |
| Ethyl Acetate | C4H8O2 | 88.11 |
| Phenol | C6H5OH | 94.11 |
| Phenolphthalein | C20H14O4 | 318.30 |
| Formaldehyde | HCHO | 30.03 |
| Glycerol (Glycerin) | C3H8O3 | 92.09 |
| D-Glucose | C6H12O6 | 180.16 |
| Hydrogen Peroxide | H2O2 | 34.02 |
| Iodine | I2 | 253.81 |
| Potassium Dihydrogen Phosphate | KH2PO4 | 136.09 |
| Potassium Dichromate | K2Cr2O7 | 294.18 |
| Potassium Hydroxide | KOH | 56.11 |
| Potassium Iodide | KI | 166.00 |
| Potassium Chloride | KCl | 74.55 |
| Potassium Chromate | K2CrO4 | 194.19 |
| Potassium Permanganate | KMnO4 | 158.03 |
| Potassium thiocyanate | KSCN | 97.18 |
| Calcium Hydroxide | Ca(OH)2 | 74.09 |
| Calcium Carbonate | CaCO3 | 100.09 |
| Calcium Chloride | CaCl2 | 110.98 |
| Calcium Oxide | CaO | 56.08 |
| Chloroform | CHCl3 | 119.37 |
| Magnesium Sulfate | MgSO4 | 120.37 |
| Methanol | CH3OH | 32.04 |
| n-Hexane | C6H14 | 86.18 |
| Naphthalene | C10H8 | 128.17 |
| Sodium Acetate | CH3COONa | 82.03 |
| Sodium Bicarbonate | NaHCO3 | 84.01 |
| Sodium Dihydrogen Phosphate | NaH2PO4 | 119.98 |
| Sodium Hydroxide | NaOH | 40.00 |
| Sodium Carbonate | Na2CO3 | 105.99 |
| Sodium Chloride | NaCl | 58.44 |
| Sodium Thiosulfate | Na2S2O3 | 158.11 |
| Paracetamol (Acetaminophen) | C8H9NO2 | 151.16 |
| Silver Nitrate | AgNO3 | 169.87 |
| Zinc Sulfate | ZnSO4 | 161.40 |
| Sucrose | C12H22O11 | 342.30 |
| Copper(II) Sulfate | CuSO4 | 159.61 |
| Toluene | C7H8 | 92.14 |
| Tris | C4H11NO3 | 121.14 |
| Urea | CH4N2O | 60.06 |
Molar masses from PubChem (NIH). Results are for planning; always check your reagent label, CoA and laboratory procedure.