Chemitey half equations

the answer is b but can someone explain why the electrons are being minused and not added?

Predict whether the changes in enthalpy, entropy, and free energy will be positive or negative for the boiling of water, and explain your predictions. how does temperature affect the spontaneity of this process?

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(ii) carbonate, in concentrated sulfuric acid. the sulfuric acid reacts with the copper(ii) carbonate to produce a blue solution of copper(ii) sulfate. scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction: (s) (aq) (s) (aq) suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. he adds powdered iron to a copper(ii) sulfate sample from the plant until no more copper will precipitate. he then washes, dries, and weighs the precipitate, and finds that it has a mass of .

What is the oxidation state of each individual carbon atom in c2o42−?