{"id":35009,"date":"2026-03-13T14:15:36","date_gmt":"2026-03-13T07:15:36","guid":{"rendered":"https:\/\/times.edu.vn\/?p=35009"},"modified":"2026-03-30T15:21:30","modified_gmt":"2026-03-30T08:21:30","slug":"igcse-chemistry-mistakes","status":"publish","type":"post","link":"https:\/\/times.edu.vn\/en\/igcse\/igcse-chemistry-mistakes\/","title":{"rendered":"IGCSE Chemistry Mistakes 2026: Common Errors Students Make and How to Avoid Them"},"content":{"rendered":"

IGCSE<\/a>\u00a0Chemistry mistakes most often come from avoidable patterns: Calculation errors (units, rounding, missing method), unbalanced equations, and forgotten state symbols. Students also lose marks by confusing key concepts such as empirical formula vs molecular formula, writing incorrect ionic equations, and mixing up covalent bonding ideas.<\/p>\n

In practical-style questions, qualitative analysis and titration errors\u2014misreading apparatus, reporting vague observations, or using non-concordant titres\u2014are major mark drains. The most effective fix is mark-scheme-led practice with a strict workflow: Show every step, carry units, state clear observations before conclusions, and standardize how you write equations and organic structures.<\/p>\n

Avoiding Common IGCSE Chemistry Mistakes in Calculations<\/strong><\/h2>\n

\"IGCSE<\/p>\n

Based on our years of practical tutoring at Times Edu, calculation errors are the fastest way strong students lose \u201ceasy\u201d marks. The issue is rarely intelligence. It is usually an incomplete method, inconsistent units, or rounding at the wrong time.<\/p>\n

The calculation mistakes examiners see every session<\/strong><\/h3>\n\n\n\n\n\n\n\n\n\n
Topic<\/strong><\/th>\nHigh-frequency IGCSE chemistry mistakes<\/strong><\/th>\nWhat the mark scheme rewards<\/strong><\/th>\nPractical fix<\/strong><\/th>\n<\/tr>\n
Mole calculations<\/td>\nMissing unit conversions; rounding too early; forgetting Mr units<\/td>\nA clear chain: Data \u2192 formula \u2192 substitution \u2192 final unit<\/td>\nKeep full calculator precision until the final line; box the final answer with units<\/td>\n<\/tr>\n
Concentration<\/td>\nConfusing cm\u00b3 vs dm\u00b3; using mass instead of moles<\/td>\nCorrect volume conversion and correct formula<\/td>\nWrite \u201c\u00f71000\u201d beside every cm\u00b3 to dm\u00b3 conversion<\/td>\n<\/tr>\n
Empirical formula<\/td>\nDividing by the wrong smallest value; forgetting to scale to integers<\/td>\nCorrect ratios, then whole-number simplification<\/td>\nAfter ratios, ask: \u201cAre they within 0.1\u20130.2 of a simple fraction?\u201d<\/td>\n<\/tr>\n
Titration<\/td>\nUsing average including rough; wrong concordant selection<\/td>\nConcordant titres only; correct mean<\/td>\nCross out rough immediately; circle concordant set<\/td>\n<\/tr>\n
Percentage yield<\/td>\nUsing theoretical in the numerator; mixing mass\/moles<\/td>\nActual \/ theoretical \u00d7 100<\/td>\nWrite the fraction first, then insert numbers<\/td>\n<\/tr>\n
Gas volume<\/td>\nTreating 24 dm\u00b3 as cm\u00b3; wrong conditions assumption<\/td>\nCorrect molar volume for stated conditions<\/td>\nUnderline conditions: RTP vs STP (only use what the question states)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

A method that prevents \u201csilent\u201d calculation errors<\/strong><\/h3>\n

A critical detail most students overlook in the 2026 exam cycle is that examiners do not \u201caward intention.\u201d They award visible chemistry. If your working is not explicit, you lose method marks even when your final number is close.<\/p>\n

Use this 5-line routine for every multi-step question:<\/p>\n