How many grams of NaCl are in 0.250 L of a 5.30 M solution, given a molar mass of 58.44 g/mol?

1. Start from the amount of solute: moles = molarity x litres. 2. That gives 5.30 mol/L x 0.250 L = 1.325 mol of NaCl. 3. Keep the trailing 5 as a guard digit rather than rounding to 1.32 mol at this stage. 4. Convert the amount to a mass: 1.325 mol x 58.44 g/mol. 5. The product is 77.4 g of NaCl. 6. Units cancel, since mol multiplied by g/mol leaves grams. 7. Rounding the intermediate to 1.32 mol first gives 77.1 g, which is the trap this calculation sets. _Source: OpenStax Chemistry (CC BY 4.0), Ch 3 "Composition of Substances and Solutions", section 3.3 Molarity_