Question

Decide whether each chemical reaction in the table below is an oxidation-reduction ("redox") reaction. If the reaction is a redox reaction, write down the formula of the reducing agent and the formula of the oxidizing agent. →+Na2CO3sH3PO4aq+Na2HPO4aq+CO2gH2Ol redox reaction?yesnoreducing agent: oxidizing agent: →+CsO2gCO2g redox reaction?yesnoreducing agent: oxidizing agent: →+2Fes3NiCl2aq+2FeCl3aq3Nis redox reaction?

Answer 1

If the reaction is a redox reaction, write down the formula of the reducing agent and the formula of the oxidizing agent.

First, let us define

Reduction = species that GAINS electrons

Oxidation = process in which a specie will LOSS electrons

Reducing agent = The species that favors reduction, i.e. it will oxidize in order to reduce another species

Oxidizing agent = The species that favors oxidation, i.e. it will reduce in order to oxidise another species

Na2CO3s + H3PO4aq--- > Na2HPO4aq+CO2g + H2Ol

Na remains +1 in both sides

H remains +1 in both sides

P remains

CO3-2 ; C + (3)(-2) = -2 --> C = +4

CO2 --> C + 2(-2) = 0; C = +4

There is no change in oxidation numbers

this is no redox

redox reaction?yes no

reducing agent: NA

oxidizing agent: NA

Cs + O2g --> CO2g

C goes from 0 to +4

O goes from 0 to -2

redox reaction?yes no

reducing agent: Must be C(s), since it is being oxidized

oxidizing agent: Must be O2(g) since it is oxidizing the carbon

2Fes + 3NiCl2aq+2FeCl3aq + 3Ni

Fe goes from 0 to +3 in FeCl3

Ni goes from +2 in NIcl2 to 0 in Ni(s)

gredox reaction?yes no

reducing agent: Fe(s)

oxidizing agent: NiCl2(aq)