Question

What is the order of enthalpy changes of these reactions from most negative to most positive?
A. P, Q, R, S
B. Q, R, S, P
C. R, Q , P, S
D. S, P, Q, R

P. Br2->2br
Q. 2Cl->Cl2
R. CH3 + Cl->CH3Cl
S. CH4-> CH3 + H

Answer 1

C-H = 410
C-Cl =340
Cl-Cl = 244
Br-Br = 193