Organic chemistry — IGCSE Physical Science (0652) questions by topic
Organic chemistry questions here compare methane and ethene by molecular structure, identify products formed when but-2-ene reacts with steam and bromine, and name substances from properties such as flammability and combustion products. State, identify, describe and explain are the command words, with state often wanting a structural reason, such as why one molecule is saturated and the other is not.
10 real questions from 2023 papers form this page, worth 1 to 11 marks. Because organic answers are marked on precise terminology, such as distinguishing coal, crude oil and petroleum from vague references to oil, submitting your responses for instant marking flags exactly which named substance or observation the mark scheme is looking for.
What examiners look for
- A recurring mistake is suggesting carbon monoxide when the question specifies complete combustion, and omitting oxygen-containing products.
- Examiners also note candidates giving oil alone rather than coal, crude oil or petroleum, stating observations the wrong way round or giving products instead of observations, and thinking fermentation uses ethene as a reactant.
- A further common misconception is that carbon dioxide causes ozone depletion, according to the reports.
- The majority of candidates correctly gave the state symbol as g, and the majority correctly circled nonanol when asked to identify it.
October–November 2023, Paper 21
What are the products of the complete combustion of methane? A carbon monoxide and hydrogen B carbon dioxide, carbon monoxide and water C carbon dioxide and water only D carbon…
Answer this question and get it marked →The formula of but-2-ene is CH₃CH=CHCH₃. But-2-ene is reacted separately with steam and with bromine. Which row identifies the structures of the products of these reactions? [A…
Answer this question and get it marked →Liquid X has the properties shown. • It is colourless. • It is flammable. • It can be made by the reaction of ethene with steam. • The complete combustion of X produces carbon…
Answer this question and get it marked →October–November 2023, Paper 22
What are the products of the complete combustion of methane? A carbon monoxide and hydrogen B carbon dioxide, carbon monoxide and water C carbon dioxide and water only D carbon…
Answer this question and get it marked →The formula of but-2-ene is CH₃CH=CHCH₃. But-2-ene is reacted separately with steam and with bromine. Which row identifies the structures of the products of these reactions? [A…
Answer this question and get it marked →Liquid X has the properties shown. • It is colourless. • It is flammable. • It can be made by the reaction of ethene with steam. • The complete combustion of X produces carbon…
Answer this question and get it marked →October–November 2023, Paper 31
Fig. 9.1 shows two organic molecules, methane (CH4, a central carbon bonded to four hydrogen atoms) and ethene (C2H4, two carbon atoms joined by a double bond, each carbon also…
Answer this question and get it marked →October–November 2023, Paper 32
Fig. 9.1 shows two organic molecules, methane (CH4, a central carbon bonded to four hydrogen atoms) and ethene (C2H4, two carbon atoms joined by a double bond, each carbon also…
Answer this question and get it marked →October–November 2023, Paper 41
Ethanol is an alcohol. The equation for the formation of ethanol from ethene is shown: C2H4(g) + H2O(....) → C2H5OH(g) Complete the equation to show the state symbol for H2O in…
Answer this question and get it marked →October–November 2023, Paper 42
Ethanol is an alcohol. The equation for the formation of ethanol from ethene is shown: C2H4(g) + H2O(....) → C2H5OH(g) Complete the equation to show the state symbol for H2O in…
Answer this question and get it marked →