please help ASAP thanku

Pt(s)/H2(g),1atmH+(aq)H+(aq)Air(a),1atmPt (a) What are the half-cell reactions? What is the overall cell reaction? What is the number of charge transfer for one mol of oxygen? (b) Estimate the value of the standard cell voltage at 25C. 9) Calculate its theoretical cell voltage according to the Nernst equation at 25C. \%) Estimate the junction potential of HCl(1M)HCl(0.2M) at 25C by using the iderson equation. 6) Please derive the electrode kinetics of H2 evolution reaction at a metal electrode ding to the following mechanisms: H++e+Mka1kc1MH(slow)MH+H++eka2kc2M+H2(fast) Pt(s)/H2(g),1atmH+(aq)H+(aq)Air(a),1atmPt (a) What are the half-cell reactions? What is the overall cell reaction? What is the number of charge transfer for one mol of oxygen? (b) Estimate the value of the standard cell voltage at 25C. 9) Calculate its theoretical cell voltage according to the Nernst equation at 25C. \%) Estimate the junction potential of HCl(1M)HCl(0.2M) at 25C by using the iderson equation. 6) Please derive the electrode kinetics of H2 evolution reaction at a metal electrode ding to the following mechanisms: H++e+Mka1kc1MH(slow)MH+H++eka2kc2M+H2(fast)