Which of the following is not a redox reaction?
a. h2o(l) + nh3(g) latex: \longrightarrow nh4+(aq) + oh–(aq)
b. 2h2(g) + o2(g) latex: \longrightarrow 2h2o(l)
c. zn(s) + h2so4(aq) latex: \longrightarrow znso4(aq) + h2(g)
d. feso4(aq) + k2cr2o7(aq) + 7h2so4(aq) latex: \longrightarrow cr2(so4)3(aq) + 3fe2(so4)3(aq) + k2so4(aq) + 7h2o(l)
e. cl2(g) + 2kbr(aq) latex: \longrightarrowbr2(l) + 2kcl(aq)