Question

The rotation about the (C2 – C3) carbon-carbon bond of n-butane requires the energy of about ___________

(a) 100 kJ/mol

(b) 50 kJ/mol

(c) 10 kJ/mol

(d) 3 kJ/mol

I got this question in examination.

Question is from Conformations in portion Structure and Stereostructure of Molecules of Engineering Chemistry I

Answer 1

Correct choice is (d) 3 kJ/mol

Explanation: The rotation about the (C2 – C3) carbon-carbon bond of n-butane requires the very less energy of about 3kJ/mol. It requires very less amount of energy.