Detergents are preferred over soaps in hard water because they:
A. Are natural
B. Are cheaper
C. Contain more carbon
D. Form soluble calcium and magnesium salts
Answer: Option D
Solution (By JKSSB Mock Tests)
Detergents (e.g., sulfonates) do not precipitate with Ca²⁺/Mg²⁺, so they lather well in hard water. Soaps form insoluble scum. This is a major advantage.
Explanation:
Natural gas (methane) is often found above petroleum deposits, trapped under cap rock. It burns cleaner than coal and oil, producing less CO₂, no SO₂, and minimal particulates. Coal (including lignite) contains more impurities. Peat is an early stage of coal. Natural gas is transported via pipelines or as LNG.
Explanation:
Calorific value is the amount of heat energy released per unit mass or volume of a fuel completely burned. Common units: J/kg, kJ/kg, kcal/kg, Btu/lb. It indicates fuel quality. Hydrogen has ~142 MJ/kg.
Explanation:
NH₃ has a lone pair on nitrogen; it donates this pair to H⁺ to form a coordinate (dative) bond, where both electrons in the bond come from nitrogen. The resulting NH₄⁺ has four equivalent N-H bonds.
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