Practical skills

Practical techniques and data analysis

Titration: rinse the burette with the solution, fill, remove the funnel, read the bottom of the meniscus at eye level to ±0.05 cm³; do a rough titre, then accurate titres until two are concordant (within 0.10 cm³); average only concordant titres. Uncertainty: each reading has an uncertainty; a burette titre uses two readings (±0.10 cm³). $\%\,\text{uncertainty}=\frac{\text{uncertainty}}{\text{value}}\times100$; add % uncertainties when quantities are multiplied or divided. Calorimetry: $q=mc\Delta T$; $\Delta H=-q/n$. Extrapolate a cooling curve to correct for heat loss. Qualitative tests: precipitates with NaOH/NH₃, gas tests, flame tests, organic functional group tests.