5-Min DSE Chemistry 化學 MCQs

DSE Chemistry works on three levels at once: what happens to particles, what a balanced equation says about amounts, and what experiments actually show. 5-Min DSE Chemistry Practice gives you 1,400 original questions for that work, each explained in English and in Traditional Chinese. THIRTEEN TOPIC AREAS Atomic structure and bonding; Planet Earth, metals and materials; mole calculations and chemical reactions; acids, bases and salts; redox and electrochemistry; fossil fuels and carbon compounds; energetics; rates; equilibrium; and periodic patterns, plus industrial, materials and analytical chemistry as electives. SHORT EXPERIMENTAL CONTEXTS Data tables describe original cases including limiting reagents, titration, copper electrolysis, cells, ester equilibrium, calorimetry, gas-volume curves, ammonia manufacture and gravimetry. Each question carries its own brief context. Practice alternates topics rather than grouping eight tasks from one case. MCQ PRACTICE All tasks use four-option multiple choice. Select a concept, a calculated value or the explanation supported by the evidence. Each short scenario and table stays with its question. Practice mixes topics and spaces related skills. Answers are checked automatically, with worked feedback. WHAT THE EXPLANATIONS TEACH Calculations follow one sequence: convert to moles, apply the equation ratio, convert back. Explanations show why reactant masses cannot be compared directly to find the limiting reagent, why a pipette is rinsed with the acid but a conical flask only with distilled water, and why a reaction that has stopped is not necessarily at equilibrium. ORGANIC AND INDUSTRIAL CHEMISTRY Carbon-compound cases link alkane combustion to pollution, ester yield to removing water, and polymer cross-linking to behaviour on heating. Industrial and analytical cases weigh yield against rate in ammonia manufacture and ask what makes a chromatogram or calibration line trustworthy. ILLUSTRATED NOTES Fourteen chapters start with the exam format and a study cycle, then give each topic an illustration, key ideas, a summary table, a worked investigation, a common-mistake callout and a recall question, such as a warning against treating relative atomic mass as a count of neutrons. TIMED SETS AND REVIEW Timed practice serves 30 questions in 35 minutes, and the built-in calculator keeps enthalpy working on screen. Scoring 15, half the set, is a practice target chosen by the app, not a pass mark from any examination body. A wrong answer stays in the mistake book until you get it right, bookmarks hold titration questions, and personal notes record traps such as forgetting to convert cm³ to dm³. LANGUAGES AND OFFLINE USE Choose English or Traditional Chinese for the interface and the questions independently, so a term such as oxidising agent can be checked in either language. Questions, notes and illustrations are installed with the app, so chemistry practice continues offline. CHEMISTRY TOPIC SPACING Particles, amounts, reaction conditions and analytical evidence are mixed through ordinary practice. The free set represents all thirteen areas at three difficulty levels. Related chemical skills are spaced apart, while an explicit topic filter keeps the session within your chosen area. PREMIUM Anyone can answer the first 100 chemistry questions. Premium opens all 1,400 and removes ads; choose a lifetime unlock or a 12-month or 3-month subscription, and the subscriptions renew automatically until you cancel them in your store account. Astera Technology Limited publishes this app independently and is not affiliated with or endorsed by the HKEAA, the EDB or any examination body. The chemistry cases, data tables and model answers are original practice material rather than official questions or past papers. Chemistry content or purchase enquiries: business@asteratek.com Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/