The hardness of water that cannot be removed by boiling is called:
A. Alkalinity
B. Softness
C. Temporary hardness
D. Permanent hardness
Answer: Option D
Solution (By JKSSB Mock Tests)
Permanent hardness is due to dissolved sulfates and chlorides of calcium and magnesium. Boiling does not remove it. It requires chemical treatment (washing soda, ion exchange) or distillation. Temporary hardness (bicarbonates) is removed by boiling.
Explanation:
Nickel (finely divided) is used as a catalyst in the hydrogenation of unsaturated vegetable oils to saturated fats (vanaspati ghee). The reaction adds H₂ across double bonds. Platinum and palladium are also hydrogenation catalysts but nickel is cheaper and industrially preferred. Fe is used in Haber process for ammonia synthesis, V₂O₅ in contact process for H₂SO₄. Catalysts provide an alternative pathway with lower activation energy.
Explanation:
This is a single displacement reaction. Iron (Fe) is more reactive than Copper (Cu), so it displaces copper from its aqueous sulfate solution. The blue color of CuSO₄ fades, and a brown deposit of Cu forms. Reactivity series dictates that a more reactive metal displaces a less reactive one.
No comments yet. Be the first to start the discussion!