Hard Practice — Advanced Set

Quick Recap — Multi-step Stoichiometry (Hard)

• Combustion analysis: moles C from $CO_2$, moles H from $H_2O$ (2 H per water); ratio $\to$ empirical formula.
• Molarity from density: $M=\dfrac{10\times\%(w/w)\times d}{\text{molar mass}}$.
• % purity: compare moles of pure substance (from product) to the sample taken.
• Mixing / limiting-reagent chains: always convert to moles first, find the limiting reagent, then carry moles through to the product.