Which of the following is an oxidation-reduction reaction? which of the following is an oxidation-reduction reaction? ba(c2h3o2)2 (aq) + na2so4 (aq) → baso4 (s) + 2nac2h3o2 (aq) cu (s) + 2agno3 (aq) → 2ag (s) + cu(no3)2 (aq) hcl (aq) + naoh (aq) → h2o (l) + nacl (aq) agno3 (aq) + hcl (aq) → agcl (s) + hno3 (aq) h2co3 (aq) + ca(no3)2 (aq) → 2hno3 (aq) + caco3 (s)

The only oxidation- reduction reaction is Cu (s) + 2AgNO3 (aq) → 2Ag (s) + Cu(NO3)2

Explanation:

An oxidation-reduction reaction is a chemical reaction that involves an electron transfer between two species. This will lead to a change in oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.

Some atoms have different possible oxidation numbers.

H has oxidation number +1

O has oxidation number -2

The oxidation number of an individual atom is 0.

The total oxidation number of all atoms in: a neutral species is 0 and in an ion is equal to the ion charge.

⇒ Ba(C2H3O2)2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaC2H3O2

(C2H3O2)2 has an oxidation number of -2. So Ba has an oxidation number of +2

In BaSO4 has SO4 an oxidation number of -2 and Ba has an oxidation number of +2

This means Ba doesn't change its oxidation number.

In Na2SO4 Na has an oxidation of +1; in NaC2H3O2 Na has an oxidation of +1

This means Na doesn't change its oxidation number.

⇒ Cu (s) + 2AgNO3 (aq) → 2Ag (s) + Cu(NO3)2

Cu has an oxidation number of 0

In Cu(NO3)2, NO3 has an oxidation number of -1 so Cu has an oxidation number of +2

In 2AgNO3, NO3 has an oxidation number of -1 so Ag has an oxidation number of +1

Ag has an oxidation number of 0

⇒ HCl (aq) + NaOH (aq) → H2O (l) + NaCl

The oxidation number of Cl and Na do not change

⇒ AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3

In AgNO3 Ag has an oxidation number of +1

In AgCl Ag has an oxidation number of +1

In HCl  Cl has an oxidation number of -1

In AgCl Cl has an oxidation number of +1

The oxidation number of Cl and Ag do not change

⇒ H2CO3 (aq) + Ca(NO3)2 (aq) → 2HNO3 (aq) + CaCO3 (s)

In Ca(NO3)2 Ca has an oxidation number of +2

In CaCO3 Ca has an oxidation number of +2

In Ca(NO3)2 N has an oxidation number of +5

In HNO3 N has an oxidation number of +5

In H2CO3  C has an oxidation number of +4

In CaCO3 C has an oxidation number of +4

The only oxidation- reduction reaction is Cu (s) + 2AgNO3 (aq) → 2Ag (s) + Cu(NO3)2

Oxidizing agent: Ag ; Reducing agent: Cu

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current