Which of the following equations describes a single-replacement reaction?

a. 2n2o5 (g) = o2 (g) + 4no2 (g)
b. 2na (s) + cl2 (g) = 2nacl (s)
c. cl2 (g) + 2kl (s) = 2kcl (s) + l2 (g)
d. h2 (g) + br2 (g) = 2hbr (g)

Option (C) is the correct answer.

Explanation:

A chemical reaction in which more reactive metal or substance displaces one less reactive metal or substance then this type of reaction is known as single displacement reaction.

Thus, we can conclude that out of the given options, the reaction equation            

As in this reaction, one chlorine atom replaces one iodine atom hence it is a single displacement reaction.

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be

fe 55.85 g/mol and h2o 18.02 g/mol.