मोलरता कैलकुलेटर
The detailed guide below is currently available in English.
From mass to molarity
A balance reads grams, but concentration lives in moles. Divide the mass by the molecular weight to get moles of solute, divide the solution volume by 1,000 if you measured it in milliliters, then split the moles by the liters: M = mass ÷ MW ÷ volume(L). The unit M (mol/L) tells you how many moles sit in every liter of solution.
Why molarity matters
Reactions happen molecule by molecule, so recipes in the lab are written in moles rather than grams. A 1 M solution carries one mole of solute per liter, which makes stoichiometry a matter of measuring volumes. Note that molarity changes slightly with temperature because liquids expand; molality (moles per kilogram of solvent) does not.
अक्सर पूछे जाने वाले प्रश्न
How do I dilute a stock solution to a target molarity?
Moles are conserved when you add solvent, so use M1V1 = M2V2. For example, to make 500 mL of 0.5 M from a 2 M stock, you need V1 = (0.5 × 500) ÷ 2 = 125 mL of stock, then dilute to the final volume.
Where do I find the molecular weight?
It is printed on the reagent bottle label and in the safety data sheet. For example, anhydrous sodium chloride is 58.44 g/mol. Our Molecular Weight Calculator can also derive it from the formula.
Does 58.44 g in 1 L really make exactly 1 M?
Yes, close enough for lab work: 58.44 ÷ 58.44 = 1 mole dissolved to a final volume of 1 liter gives 1 mol/L. In practice you dissolve first, then top up to the mark, because the added solid changes the volume slightly.