Q: Calcium oxide reacts vigorously with water to produce slaked lime whose solution is used for white-washing walls. This slaked lime reacts with component (A) in air to form a thin layer of component (B) to give a shiny finish. What are the components (A) and (B)?
(a)A – O2 ; B – CaCO3
(b)A – CO2 ; B – Ca(OH)2
(c)A – O2 ; B – Ca(OH)2
(d)A – CO2 ; B – CaCO3
Correct Answer: (d)
The correct answer is (b) 'A – CO2 ; B – Ca(OH)2'. This question from the Environment & Ecology domain tests knowledge of Climate Change & Greenhouse Gases.