In the redox reaction below, which is the reducing agent? mno2 (s) + 4h+(aq) + 2cl (aq) > mn2+(aq) + 2h2o(l) + cl2(g) ci- ci2 mn2+ mno2 i think its mno2? ,

Chlorine loses electrons to form cl2. in order to do this the chlorine oxidizes. to oxidize is to lose electrons and to reduce is to gain electrons therefore the chlorine is the reducer in the equation. anytime an item experiences a decrease in oxidation it means that it is reduced. therefore the chlorine is the reducer.

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na