Order of reactivity of alcohols towards sodium metal is:

Concept:

The acidity of alcohols:

• Just as metals react with acids to liberate hydrogen, alcohols react with metals to liberate hydrogen acting as an acid.
• The conjugate base alkoxide ion formed after alcohol releases a proton is R -O ^-.
• The stability of the conjugate base depends on the +I of the alkyl group R attached because it is not resonance stabilized here.
• The strength of negative charge increases as we move on from primary to secondary to tertiary alcohols because of the number of alkyl groups increases.
• The increase in negative charge over the oxygen atom destabilizes the conjugate base.
• Thus, the acidity of alcohols follows the order Primary> Secondary > Tertiary.
• 

Explanation:

• In the reaction of alcohols with sodium metal, bond cleavage of the O - H bond takes place.
• The ease of breakage of the O-H bond in alcohols is an indication of the acidity of alcohols.

 We know that the ease of this bond breakage follows the order primary > secondary > tertiary.

So, the ease of reactivity of sodium follow the order