What are the cell reactions and their emfs in the following systems? are the reactions spontaneous? assume that all systems are aqueous. (a) ag/agcl/k+, cl- (1 m)/hg2cl2/hg (b) pt/fe3+ (0.01 m), fe2+ (0.1 m), hcl (1 m)//cu2+ (0.1 m), hcl (1 m)/cu (c) pt/h2 (1 atm)/ h+ , cl- (0.1 m)// h+ , cl- (0.1 m)/o2 (0.2 atm/pt (d) pt/h2 (1 atm)/na+ , oh- (0.1 m)// na+ , oh- (0.1 m)/o2 (0.2 atm)/pt (e) ag/agcl/k+ , cl- (1 m)// k+ , cl- (0.1 m)/ agcl/ ag (f) pt/ ce3+ (0.01 m), ce4+ (0.1 m), h2so4 (1 m) // fe2+ (0.01 m), fe3+ (0.1 m), hcl (1 m)/ pt