Chemistry
Solve molarity and dilution problems with unit conversions done for you, and count, round and calculate with significant figures.
The three formulas behind these calculators
- Molarity: M = moles of solute ÷ liters of solution, and moles = grams ÷ molar mass.
- Dilution: C₁V₁ = C₂V₂. The amount of solute stays the same; only the volume changes.
- Significant figures: multiply and divide to the fewest significant figures; add and subtract to the fewest decimal places.
Common questions
How do you make a solution of a given molarity?
Multiply the molarity by the volume in liters to get moles, then by the molar mass to get grams. For 250 mL of 0.100 M NaCl: 0.100 × 0.250 × 58.44 = 1.46 g, dissolved and made up to 250 mL.
How many significant figures should my answer have?
For multiplication and division, use the fewest significant figures in the data. For addition and subtraction, use the fewest decimal places. 4.56 × 1.4 = 6.4, and 12.11 + 18.0 = 30.1.