Chemie begreifen

Chemie begreifen makes upper-secondary chemistry make sense — not by
memorizing, but by working with the quantities and seeing immediately what
happens. The app is in German.

Written for upper-secondary students, explicitly including those who have
lost the thread. Next to every technical term sits an info button. One tap
brings up a plain-language explanation with a worked example and links down
to the underlying basics. You don't need to know what to search for — the
explanation is right where the term appears.

PERIODIC TABLE
All 118 elements, tappable, with atomic number, molar mass, electron
configuration, shell occupation and electronegativity. Switch the colouring
between substance class, electronegativity and state of matter. Search by
name, symbol or atomic number.

LABORATORY
Tap two elements and see what forms: which salt, which electrons move, why
the ratio is exactly what it is. Plus over twenty verified reactions from
the oxyhydrogen reaction through the Haber-Bosch process to photosynthesis,
each with conditions, energy balance and everyday relevance.

STOICHIOMETRY
Molar mass from any formula including brackets and water of crystallization,
with the calculation broken down rather than just an answer. Conversion
between mass, amount of substance, particle number and gas volume. Solution
preparation and dilution. And an equation balancer that solves rather than
guesses.

ACIDS AND BASES
pH values for strong and weak acids, buffers via Henderson-Hasselbalch, and
titration curves with equivalence and half-equivalence points. The
school-level approximation and the exact value always appear side by side —
along with a note on whether the approximation holds here at all.

REDOX AND ELECTROCHEMISTRY
Oxidation numbers for any formula, derived step by step rather than looked
up. Analyse reactions to see what is oxidized and what is reduced.
Electrochemical series, cell voltage, the Nernst equation and Faraday's laws.

ORGANIC CHEMISTRY
Pick a substance class and chain length, and the name, molecular formula,
condensed formula and drawn skeletal formula follow from it. The name is not
vocabulary but a set of building instructions — and that becomes visible
here. Plus homologous series with boiling point trends and isomer counts.

WHAT THIS APP DOES NOT DO
It never invents anything. Where a result cannot be derived soundly, it says
so and explains why, instead of producing a plausible-looking but wrong
answer. For exam preparation, an honest gap is worth more than a fabricated
answer.

The calculation logic is machine-verified: over four thousand automated
checks compare molar masses, balances, pH values, oxidation numbers and
nomenclature against reference values before any version is built.

PRIVACY
Chemie begreifen collects no personal data whatsoever. No accounts, no ads,
no in-app purchases, no tracking, no internet connection required. Inputs
stay temporarily on your device only.

DISCLAIMER
An aid for learning chemistry. It does not replace safety instruction or
hazard labelling — practical experiments belong under expert supervision.