Which equation represents a redox reaction? 2Na+ + 2- → Na2S
2.
H+ + C2H302 → HC2H302
3.
NH3 + H+ + Cl- + NH4+ + Cl-
4.
Cu + 2Ag+ + 2NO3 – 2Ag + Cu2+ + 2NO3-

Achemist 16 drop copper metal from copper chloride solution. the chemist place is 0.50 g of aluminum foil in a solution containing 0.75 g of copper (ii) chloride. a single replacement reaction takes place. which statement explains the maximum amount of copper that the chemist can extract using this reaction?