Air and atmosphere
21 past-paper questions on Air and atmosphere · examined 2020–2025.
20255 questions
2 Which substance would diffuse most quickly? A carbon dioxide at 0 °C B carbon dioxide at 25 °C C neon at 0 °C D neon at 25 °C
© UCLES 2025 5070/11/O/N/25 [Turn over 13 Which row is correct? purpose of hydrogen–oxygen fuel cell chemical product of hydrogen–oxygen fuel cell A to recycle waste hydrogen B to recycle waste water C to produce electrical energy hydrogen D to produce electrical energy water 6
29 Carbon dioxide, methane and oxygen are gases involved in the carbon cycle. Which of these gases cause global warming? A carbon dioxide only B carbon dioxide and methane C carbon dioxide and oxygen D methane only l ?
State the percentage by volume of oxygen in clean, dry air.
5070/22/M/J/25 © UCLES 2025 5 The combustion of fossil fuels is used in some power stations. (a) Some power stations use diesel oil as a fuel. (i) One compound in diesel oil has the formula C 12 H 26 . Construct the symbol equation to show the complete combustion of C 12 H 26 . ..................................................................................................................................... [1] (ii) The complete combustion of C 12 H 26 produces an air pollutant. State one adverse effect of this pollutant. ......................................................................
20233 questions
17 The combustion of methane is a redox reaction. CH4 + 2O2 CO2 + 2H2O Which statement about this reaction is correct? A Only carbon is oxidised. B Only carbon is reduced. C Only oxygen is oxidised. D Only oxygen is reduced.
© UCLES 2023 5070/12/O/N/23 [Turn over 14 Nitrogen and oxygen react as shown. N2(g) + 2O2(g) 2NO2(g) The enthalpy change for the reaction shown is +66 kJ. If two moles of nitrogen and two moles of oxygen are used, what will be the enthalpy change? A +16.5 kJ B +33 kJ C +66 kJ D +132 kJ 6
5070/21/O/N/23 © UCLES 2023 [Turn over 1 Choose from the list of compounds to answer these questions. calcium oxide carbon dioxide carbon monoxide lead chloride propan‑1‑ol sodium nitrate sodium sulfate sulfur dioxide water Each compound may be used once, more than once or not at all. Identify the compound that: (a) is a toxic gas produced by the incomplete combustion of carbon‑containing compounds ............................................................................................................................................. [1] (b) turns anhydrous copper( II ) sulfate blue ......
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