CIE iGCSE Co-Ordinated Science C10.2 Air quality and climate Exam Style Questions Paper 1
▶️ Answer/Explanation
Clean, dry air is composed of approximately 78% nitrogen and 21% oxygen, with the remaining 1% consisting of noble gases and carbon dioxide. In the diagram, gas X represents the larger portion, which is nitrogen (78%), and gas Y represents the smaller portion, which is oxygen (21%). Therefore, row A correctly identifies gas X as nitrogen and gas Y as oxygen.
✅ Answer: (A)
✅ Answer: (A)
▶️ Answer/Explanation
Car engines produce carbon monoxide (incomplete combustion), oxides of nitrogen (from high‑temperature reaction of nitrogen and oxygen in air), and sulfur dioxide (if the fuel contains sulfur impurities). All three are produced, so option A is correct.
✅ Answer: (A)
✅ Answer: (A)
▶️ Answer/Explanation
Clean air is approximately 21% oxygen by volume.
Let the total volume be \(V\); then \(0.21 \times V = 10.5\), so \(V = \dfrac{10.5}{0.21} = 50\).
A volume of 50 cm\(^{3}\) of clean air contains 10.5 cm\(^{3}\) of oxygen.
✅ Answer: (C)
Let the total volume be \(V\); then \(0.21 \times V = 10.5\), so \(V = \dfrac{10.5}{0.21} = 50\).
A volume of 50 cm\(^{3}\) of clean air contains 10.5 cm\(^{3}\) of oxygen.
✅ Answer: (C)
▶️ Answer/Explanation
After removing water vapour (~variable), \(\text{CO}_2\) (~0.04%), and noble gases (~1%), what remains is nitrogen (~78%) and oxygen (~21%), which together account for approximately 99 cm³ out of 100 cm³.
The removed components total roughly 1 cm³, so the remaining volume is approximately \(100 – 1 = 99 \text{ cm}^3\).
✅ Answer: (D)
The removed components total roughly 1 cm³, so the remaining volume is approximately \(100 – 1 = 99 \text{ cm}^3\).
✅ Answer: (D)
▶️ Answer/Explanation
Clean, dry air is made up mainly of nitrogen and oxygen, with small proportions of other naturally occurring gases including carbon dioxide.
Carbon monoxide, nitrogen dioxide and sulfur dioxide are all pollutant gases produced by human activities such as combustion, and are not natural components of clean air.
Carbon dioxide, in contrast, is naturally present in air at a low but constant concentration.
✅ Answer: (A)
Carbon monoxide, nitrogen dioxide and sulfur dioxide are all pollutant gases produced by human activities such as combustion, and are not natural components of clean air.
Carbon dioxide, in contrast, is naturally present in air at a low but constant concentration.
✅ Answer: (A)