Organic chemistry written questions
Write G2 Chemistry answers on hydrocarbons, fuels and polymers, checking structures, reactions and explanations against marking guidance.
Learning goals
- Name natural gas, mainly methane, and crude oil as non-renewable energy sources
- Describe crude oil as a mixture of hydrocarbons separated by fractional distillation into fractions used as fuels and as a source of chemicals
- Describe biofuels, such as bioethanol from sugarcane, as a renewable alternative to natural gas and crude oil
- Describe how biofuels are more sustainable than fossil fuels because plants take in carbon dioxide as they grow, offsetting what burning releases
- Describe a homologous series as compounds with a general formula, similar chemical properties and physical properties that change gradually as the molecules get bigger
- Describe the alkanes as a homologous series of saturated hydrocarbons with general formula CₙH₂ₙ₊₂
- Draw and name the unbranched alkanes methane to propane
- Describe alkanes, such as methane, as generally unreactive apart from combustion and substitution by chlorine
- Describe the alkenes as a homologous series of unsaturated hydrocarbons with general formula CₙH₂ₙ
- Draw and name the unbranched alkenes ethene and propene
- Describe how cracking makes alkenes and hydrogen, and why cracking is needed to meet demand for fractions of smaller molecules
- Distinguish saturated from unsaturated hydrocarbons by their structures and with aqueous bromine
- Describe the combustion, polymerisation and addition reactions with bromine and hydrogen of alkenes such as ethene
- State what polyunsaturated means on food products
- Describe how margarine is made by adding hydrogen to unsaturated vegetable oils to form a solid
- Describe polymers as large molecules built from small monomer units, with different polymers having different units
- Describe how ethene monomers form poly(ethene) by addition polymerisation
- State uses of poly(ethene) as a typical plastic, such as plastic bags and cling film
- Deduce an addition polymer's structure from its monomer, and the reverse
- Describe the pollution caused by disposing of non-biodegradable plastics
- Describe physical recycling of plastics, such as melting poly(ethene) waste into pellets
- Describe chemical recycling of plastics, such as cracking plastic waste into fuel
- Discuss the social, economic and environmental issues of recycling plastics
Use the feedback to improve your answers; this practice does not count towards your progress.
Time is up and your answers could not be submitted; check your connection and try again.
Paper instructions
Practise
Practise questions on the skills you are learning. This is for practice only and doesn’t count towards your course progress.
- Question count is checked before you start.
- About 10 minutes.
- Feedback appears after you check each answer.
Your work
Without an account, unfinished answers stay in this tab. Signed in, they are saved on this device until the deadline shown when you start.
Getting your questions…
Recent attempts
History is stored only in this browser.
No completed attempts are saved yet.
Beyond the syllabus: optional enrichment that does not count towards your progress.