Question 1

What is molarity?

Accepted Answer

Molarity (M) is the number of moles of solute dissolved per liter of solution: M = moles/liters. A 1 M (1 molar) solution contains 1 mole of solute in exactly 1 liter of total solution. Molarity is the most common unit of concentration in chemistry labs.

Question 2

How do I calculate grams of solute from molarity?

Accepted Answer

Grams = M × V(L) × MW. Example: to make 500 mL of 0.1 M NaCl (MW = 58.44 g/mol): grams = 0.1 mol/L × 0.5 L × 58.44 g/mol = 2.922 g. Dissolve 2.922 g NaCl in water and bring to 500 mL total volume.

Question 3

What is the dilution formula?

Accepted Answer

C₁V₁ = C₂V₂ (initial concentration × initial volume = final concentration × final volume). To dilute a 6 M HCl stock to 0.5 M, 200 mL: V₁ = (0.5 × 200) / 6 = 16.67 mL. Add 16.67 mL of stock to a flask, then add water to reach 200 mL total.

Question 4

What is the difference between molarity, molality, and normality?

Accepted Answer

Molarity (M) = moles/liter of solution — most common. Molality (m) = moles/kilogram of solvent — used for colligative properties (boiling point elevation, etc.) because it is temperature-independent. Normality (N) = equivalents/liter — used in acid-base and redox chemistry where one mole may not equal one equivalent.

Question 5

Should I consult a chemist for solution preparation?

Accepted Answer

For research-grade, pharmaceutical, or hazardous chemical solutions, always have a qualified chemist or pharmacist verify your calculations and preparation procedure. Errors in concentration can invalidate experiments or cause safety incidents. Double-check calculations independently before preparing any hazardous solution.

Molarity Calculator