The half reaction of an oxidation-reduction shows that iron gains electrons. what does this electron gain mean for iron? a. it’s neutralized
b. it’s oxidized
c. it has dissolved
d. it’s reduced
e. it has precipitated

d. it’s reduced

Explanation:

An oxidation-reduction reaction, commonly known as REDOX reaction is a type of reaction that involves the transfer of electrons from one atom to another characterized by a change in oxidation number. The atom that loses electrons is said to be OXIDIZED while the atom that gains electrons is said to be REDUCED.

Therefore, in this question describing the half reaction of an oxidation reduction to show that iron atom (Fe) gains electrons. This indicates that the IRON atom is being REDUCED because it's oxidation number will reduce after gaining electrons.

fe 55.85 g/mol and h2o 18.02 g/mol.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.