Medium Practice — Set 2

Quick Recap — Formulae from Data, Mixing & More

• Empirical formula from %: divide each element's % by its atomic mass, then take the simplest ratio.
• Mixing same solute: $M_{mix}=\dfrac{M_1V_1+M_2V_2}{V_1+V_2}$.
• Molarity of pure water $\approx\dfrac{1000}{18}=55.5$ M.
• Mass % of an element / water of crystallisation works off the molar mass, exactly like composition.