User Forum

Subject :NSO    Class : Class 10

Which of the following statements are incorrect?
I. Reactivity of Al decreases if it is dipped in nitric acid.
II. Carbon can reduce the oxides of Na and Mg.
III. NaCl is a good conductor of electricity in solid state.
IV. Metals like K, Ca and Mg are always found in free state in nature.

A I, II and III only
B II, III and IV only
C I and III only
D II and III only


common salt can never conduct electricity in solid state

Ans 1:

Class : Class 10
B) II,III,IV CARBON can reduce oxides of metals lower in the activity series. K, Ca and Mg are high in the activity series so they are very reactive so they can not be found in free state easily.

Post Your Answer