The metal that does not react with dilute hydrochloric acid to produce hydrogen is:
A. Ag
B. Mg
C. Al
D. Fe
Answer: Option A
Solution (By JKExamLibrary)
Silver (Ag) is a noble metal below hydrogen in the reactivity series and does not displace H₂ from dilute acids. Mg, Al, Fe are above H and react: Mg + 2HCl → MgCl₂ + H₂. However, Al reacts slowly initially due to oxide layer. Copper also doesn't react. The reactivity series determines acid reactivity.
Explanation:
A decomposition reaction is one where a single compound breaks down into two or more simpler substances. Heating potassium chlorate (KClO₃) breaks it down into potassium chloride and oxygen gas. A is combination, C is displacement, and D is double displacement.
Explanation:
Iodine directly converts from solid to violet vapor on gentle heating (sublimation). NaCl melts; sugar decomposes; copper melts at high temperature. Other sublimable substances: camphor, naphthalene, dry ice.
Explanation:
The ozone layer is located in the lower stratosphere (~15-35 km altitude), where ozone concentration is highest. It absorbs harmful ultraviolet radiation (UV-B and UV-C) from the sun. Ground-level ozone (troposphere) is a pollutant and component of smog, harmful to health. Ozone depletion is caused by chlorofluorocarbons (CFCs) which release chlorine atoms that catalytically destroy O₃.
No comments yet. Be the first to start the discussion!