Consider the half reactions below for a chemical reaction. Zn——>Zn2+ (aq) + 2e-
Cu2+ (aq) + 2e- ——> Cu(s)
What is the overall equation for this chemical reaction?
Zn(s)+ Cu2+ (aq)
Zn2+ (aq) + Cu(s)
Zn(s) + Cu2+ (aq) Cu2+ (aq) + 2e-
Zn2+ (aq) + Cu(s)-> Cu2+ (aq) + Zn(s)
Zn2+ (aq) + 2e--> Cu2+ (aq) + 2e-

Decomposition is the cycle at which bacteria breaks down any organic material into the soil

According to arrhenius theory of acid and bases, an acid is a proton donor, while base donates hydroxyl ions. further, acid and base reacts to form salt and water.consider following example.hcl    +      h2o          →      cl-          +      h3o+here, hcl has donated a proton, hence it is an acid.now consider following reactionhcl      +      naoh            ↔      nacl      +        h2oin this reaction, hcl donates proton, hence it is acid. on other hand, naoh donates hydroxyl ion (i.e. hence it is a base.   

Electron equations of the given changes are as follow,a)                              cu      →      cu⁺²  + 2e⁻b)                              mg⁺²  +  2 e⁻      →      mgc)                              cl⁻    →      cl  +  1e⁻d)                              s  +  2 e⁻    →      s²⁻e)                                o²⁻      →      o  +  2 e⁻f)                              p  +  3 e⁻    →      p³⁻g)                              fe²⁺    →      fe³⁺  + 1 e⁻h)                              s²⁻    →      s⁴⁺  +  6 e⁻