Which allotrope of carbon is used as a neutron moderator in nuclear reactors?
A. Graphite
B. Charcoal
C. Fullerene
D. Diamond
Answer: Option A
Solution (By JKExamLibrary)
Graphite slows down fast neutrons in nuclear reactors, enabling sustained chain reaction. Diamond is hard and insulating; fullerenes are nanomaterials; charcoal is adsorbent.
Explanation:
Global warming is the long-term rise in Earth's average temperature, primarily caused by the increased concentration of greenhouse gases (like CO₂, CH₄, N₂O) in the atmosphere. These gases trap outgoing infrared radiation, enhancing the natural greenhouse effect and leading to climate change.
Explanation:
Ostwald process: ammonia is oxidized with air over Pt-Rh catalyst to NO, then NO₂, then absorbed in water to give HNO₃. Haber for NH₃, Contact for H₂SO₄, Bayer for alumina from bauxite.
Explanation:
Sodium bicarbonate (NaHCO₃) is used in soda-acid fire extinguishers. It reacts with sulfuric acid to produce CO₂, which smothers the fire. Also, dry powder extinguishers use NaHCO₃. It is also baking soda.
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