Question

Which of the following statements are incorrect? 

l. Reactivity of Al decreases if it is dipped in nitric acid. 

ll. Carbon can reduce the oxides of Na and Mg. 

lll. NaCl is a good conductor of electricity in solid state. 

lV. Metals like K, Ca and Mg are always found in free state in nature.

(A) I, ll and III only 

(B) ll, lll and lV only 

(C) I and lll only 

(D) ll and lll only

Answer 1

Correct option  (B) ll, lll and lV only 

Explanation: 

AI becomes passive if it is dipped in nitric acid due to formation of a protective layer of aluminium oxide. Carbon cannot reduce the oxides of Na or Mg 

NaCl is a good conductor of electricity in molten state or in aqueous solution.

Metals like K, Ca and Mg are highly reactive and are never found in free state in nature.