The separation technique that uses a porous barrier to separate solids from liquids is:
A. Distillation
B. Filtration
C. Sublimation
D. Chromatography
Answer: Option B
Solution (By JKSSB Mock Tests)
Filtration uses filter paper or other porous medium that allows liquid to pass but retains solid particles. Distillation separates liquids by boiling points; sublimation separates sublimable solids; chromatography separates based on differential adsorption. Example: separating sand from water.
Explanation:
At cathode (negative electrode), H⁺ ions are reduced: 2H⁺ + 2e⁻ → H₂(g). At anode (positive), water is oxidized: 2H₂O → O₂ + 4H⁺ + 4e⁻. Overall: 2H₂O → 2H₂ + O₂. The volume of H₂ collected is double that of O₂. Acidified water (with H₂SO₄) enhances conductivity. Platinum electrodes are used.
Explanation:
Manganese is extracted by the aluminothermic process (Goldschmidt thermite process) where Mn₃O₄ is reduced by aluminium: 3Mn₃O₄ + 8Al → 9Mn + 4Al₂O₃. This works for metals with less reactivity than Al but not too reactive. Sodium is extracted by electrolysis. Iron is extracted by smelting with coke. Zinc by carbon reduction/electrolysis.
Explanation:
H₂O₂ decomposes when exposed to light (photochemical decomposition): 2H₂O₂ → 2H₂O + O₂. Light provides energy to break the O–O bond. To prevent decomposition, it is stored in amber or opaque bottles, often with stabilizers like urea or phosphoric acid. Also, traces of heavy metal ions catalyze decomposition. H₂O₂ is a strong oxidizing agent and bleaching agent.
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