Which of the following answer correctly identifies the reduction-oxidation reaction below and gives the correct reasoning? *The choices are shown in image

Answer choices-

a )Reaction I. The oxidation state of Na(s) and Cl2(g) both change.
b) Reaction II. The Co2+ in Co(NO3)2 (aq) changes from aqueous to solid in CoI2 (s).
c) Reaction III. The C in NaHCO3 (s) changes to a gas in CO2 (g).
d) Reaction IV. The sodium is changing state.

The correct answer : reaction 1

Given

Chemical reaction

Required

The reduction-oxidation reaction

Solution

The reduction-oxidation reaction

Na oxidation, from 0 to +1

Cl reduction, from 0 to -1

The oxidation number of Co does not change, remains +2, and the reaction is not oxidation-reduction but double displacement

The oxidation number C does not change constantly +4 in either NaHCO3 or CO2 compounds, and the reaction is a decomposition reaction

The oxidation number of Na remains unchanged at +1 in either NaOH or NaC2H3O2 compounds, and the reaction is a neutralization reaction

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.