Chemkit

Analytical chemistry

Titration curves, pH and normality of acid–base systems, Beer–Lambert absorbance, chromatography retention, and calibration regression.

7 guides 3 calculators 1 cheat sheet

Reading path

Start here. Each guide is a self-contained tutorial with worked examples and cited sources.

  1. When Beer-Lambert lies Concentration limits, scattering, stray light, chemical speciation — the five ways the A = εbc line stops being a line. 10 min
  2. Calibration curves without lying to yourself Build a regression that survives an audit: LOD, LOQ, confidence interval, residual plot, and when to switch to standard addition. 12 min
  3. Reading titration curves: what the shape tells you Buffer plateaus, equivalence points, and half-equivalence-point pH — the shape of the curve names the analyte and gives the pKa for free. 12 min
  4. Reading an HPLC chromatogram: retention and resolution Retention, plate count, resolution, peak shape — the four numbers that grade any HPLC separation. 12 min
  5. Reading a mass spectrum: fragments and isotopes The molecular ion names the mass; the fragment pattern names the connectivity; the isotope satellites name the elements. 13 min
  6. IR spectroscopy: reading the functional-group region The 4000-1500 window names the functional groups; the fingerprint below 1500 confirms the identity. A four-question workflow reads any spectrum. 12 min
  7. Analytical statistics: mean, SD, and the t-test Every measurement is a random variable. Mean, standard deviation, standard error, confidence interval, t-test, and outlier rejection — in one workflow. 12 min

Calculators

Cheat sheets