Question 1: Define combustion in the context of organic chemistry.

Answer: Combustion is a chemical reaction where a hydrocarbon reacts with oxygen to produce carbon dioxide, water, and energy (heat and light).

Question 2: Explain why complete combustion of hydrocarbons produces carbon dioxide and water, whereas incomplete combustion produces carbon monoxide and soot.

Answer: Complete combustion occurs when there is sufficient oxygen, fully oxidising hydrocarbons to carbon dioxide and water. Incomplete combustion occurs when oxygen is limited, leading to partial oxidation and formation of carbon monoxide and soot (carbon particles).

Question 3: Describe the role of hydrocarbons from crude oil in powering nanotechnology devices that require high energy densities.

Answer: Hydrocarbons from crude oil can be combusted to release large amounts of energy, which can be harnessed in nanotechnology applications such as micro-robots or energy storage systems requiring compact, high-density power sources.

Question 1: Calculate the amount of carbon dioxide produced when 2 moles of methane (CH4) undergo complete combustion. (Use the reaction: CH4 + 2O2 → CO2 + 2H2O).

Answer: 2 moles of CH4 produce 2 moles of CO2; thus, 2 moles of methane produce 2 moles of CO2.

Question 2: If 16 grams of methane undergo complete combustion, calculate the volume of carbon dioxide produced at room temperature and pressure (assume ideal gas behaviour, molar volume = 24 dm³).

Answer: Moles of CH4 = 16 g / 16 g/mol = 1 mol; CO2 produced = 1 mol; Volume = 1 mol × 24 dm³ = 24 dm³.

Question 1: Describe a simple experimental setup to investigate the complete combustion of a hydrocarbon vapour, including variables to control and safety precautions.

Answer: An experimental setup would include a combustion chamber with a hydrocarbon fuel source, oxygen supply, and a heat-resistant surface. Variables to control include fuel flow rate, oxygen supply, and temperature. Safety precautions involve using a fume hood, wearing protective goggles, and ensuring proper ventilation to prevent inhalation of harmful gases and fire hazards.

Question 1: A nanotechnology company aims to develop micro-heat engines powered by combustion of hydrocarbon vapours derived from crude oil. Discuss the advantages and challenges of using combustion-based energy sources in nanotechnology devices.

Answer: Advantages include high energy density and portability, enabling compact power sources for nanodevices. Challenges involve managing heat and exhaust gases at a microscopic scale, ensuring safety, and preventing damage to delicate nanostructures. Efficient and clean combustion processes are essential to minimise pollution and thermal damage.

Question 2: In a scenario where incomplete combustion occurs in a nanotech-powered system, what are the potential impacts on device performance and emissions?

Answer: Incomplete combustion can lead to reduced energy efficiency, accumulation of carbon monoxide and soot, and increased emissions of harmful pollutants, which may damage the nanodevices and pose health hazards.