Assertion (A): Aluminum is highly reactive but is used for making cooking utensils. Reason (R): Aluminum forms a protective layer of aluminum oxide on its surface. MCQ with Answer and Explanation
Assertion (A): Aluminum is highly reactive but is used for making cooking utensils. Reason (R): Aluminum forms a protective layer of aluminum oxide on its surface.
A. Both A and R are true but R is NOT the correct explanation of A.
B. Both A and R are true and R is the correct explanation of A.
C. A is false but R is true.
D. A is true but R is false.
Answer: Option B
Solution (By JKSSB Mock Tests)
Aluminum is a highly reactive metal, yet it is widely used for cookware. This is because it rapidly reacts with atmospheric oxygen to form a thin, tough, and invisible layer of aluminum oxide (Al2O3) on its surface. This passivation layer prevents further corrosion and reaction with food.
Explanation:
Lower activation energy means more molecules have energy to cross the barrier, increasing the reaction rate. Enthalpy (ΔH) and equilibrium constant remain unchanged. Catalyst does not affect stoichiometry.
Explanation:
Charles' law: V ∝ T (Kelvin) at constant P and n. V/T = constant. This means if temperature is doubled (in Kelvin), volume doubles. Temperature must be in Kelvin (K = °C + 273). Graph of V vs T is a straight line passing through origin. This law is used in hot air balloons: heated air expands, decreasing density, providing lift. Combined with Boyle's law gives PV = nRT.
No comments yet. Be the first to start the discussion!